From patchwork Wed Apr 27 05:48:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828297 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94EB0C433F5 for ; Wed, 27 Apr 2022 05:57:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357932AbiD0GAw (ORCPT ); Wed, 27 Apr 2022 02:00:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357916AbiD0GAv (ORCPT ); Wed, 27 Apr 2022 02:00:51 -0400 X-Greylist: delayed 490 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 26 Apr 2022 22:57:41 PDT Received: from mailout1.hostsharing.net (mailout1.hostsharing.net [83.223.95.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E4792DD57; Tue, 26 Apr 2022 22:57:41 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout1.hostsharing.net (Postfix) with ESMTPS id DBB1110057928; Wed, 27 Apr 2022 07:57:39 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id AA58E61ABA99; Wed, 27 Apr 2022 07:57:39 +0200 (CEST) X-Mailbox-Line: From ca65428c57c0b15ead00c92decb9b4a01a0fa81f Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:01 +0200 Subject: [PATCH net-next 1/7] usbnet: Run unregister_netdev() before unbind() again To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Commit 2c9d6c2b871d ("usbnet: run unbind() before unregister_netdev()") sought to fix a use-after-free on disconnect of USB Ethernet adapters. It turns out that a different fix is necessary to address the issue: https://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650177997.git.lukas@wunner.de/ So the commit was not necessary. The commit made binding and unbinding of USB Ethernet asymmetrical: Before, usbnet_probe() first invoked the ->bind() callback and then register_netdev(). usbnet_disconnect() mirrored that by first invoking unregister_netdev() and then ->unbind(). Since the commit, the order in usbnet_disconnect() is reversed and no longer mirrors usbnet_probe(). One consequence is that a PHY disconnected (and stopped) in ->unbind() is afterwards stopped once more by unregister_netdev() as it closes the netdev before unregistering. That necessitates a contortion in ->stop() because the PHY may only be stopped if it hasn't already been disconnected. Reverting the commit allows making the call to phy_stop() unconditional in ->stop(). Signed-off-by: Lukas Wunner Cc: Oleksij Rempel Cc: Martyn Welch Cc: Andrew Lunn Acked-by: Oliver Neukum --- drivers/net/usb/asix_devices.c | 6 +----- drivers/net/usb/smsc95xx.c | 3 +-- drivers/net/usb/usbnet.c | 6 +++--- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 38e47a93fb83..5b5eb630c4b7 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -795,11 +795,7 @@ static int ax88772_stop(struct usbnet *dev) { struct asix_common_private *priv = dev->driver_priv; - /* On unplugged USB, we will get MDIO communication errors and the - * PHY will be set in to PHY_HALTED state. - */ - if (priv->phydev->state != PHY_HALTED) - phy_stop(priv->phydev); + phy_stop(priv->phydev); return 0; } diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 4ef61f6b85df..edf0492ad489 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1243,8 +1243,7 @@ static int smsc95xx_start_phy(struct usbnet *dev) static int smsc95xx_stop(struct usbnet *dev) { - if (dev->net->phydev) - phy_stop(dev->net->phydev); + phy_stop(dev->net->phydev); return 0; } diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 9a6450f796dc..36b24ec11650 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1616,9 +1616,6 @@ void usbnet_disconnect (struct usb_interface *intf) xdev->bus->bus_name, xdev->devpath, dev->driver_info->description); - if (dev->driver_info->unbind) - dev->driver_info->unbind(dev, intf); - net = dev->net; unregister_netdev (net); @@ -1626,6 +1623,9 @@ void usbnet_disconnect (struct usb_interface *intf) usb_scuttle_anchored_urbs(&dev->deferred); + if (dev->driver_info->unbind) + dev->driver_info->unbind(dev, intf); + usb_kill_urb(dev->interrupt); usb_free_urb(dev->interrupt); kfree(dev->padding_pkt); From patchwork Wed Apr 27 05:48:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828300 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F9A2C433F5 for ; Wed, 27 Apr 2022 05:59:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357940AbiD0GCx (ORCPT ); Wed, 27 Apr 2022 02:02:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242834AbiD0GCw (ORCPT ); Wed, 27 Apr 2022 02:02:52 -0400 Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [IPv6:2a01:4f8:150:2161:1:b009:f236:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BC383D1F7; Tue, 26 Apr 2022 22:59:42 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 17778100DECB3; Wed, 27 Apr 2022 07:59:40 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id CDAA561ABA99; Wed, 27 Apr 2022 07:59:39 +0200 (CEST) X-Mailbox-Line: From 91a3499156cff9123ede28c95e802d47f4151141 Mon Sep 17 00:00:00 2001 Message-Id: <91a3499156cff9123ede28c95e802d47f4151141.1651037513.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:02 +0200 Subject: [PATCH net-next 2/7] usbnet: smsc95xx: Don't clear read-only PHY interrupt To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Upon receiving data from the Interrupt Endpoint, the SMSC LAN95xx driver attempts to clear the signaled interrupts by writing "all ones" to the Interrupt Status Register. However the driver only ever enables a single type of interrupt, namely the PHY Interrupt. And according to page 119 of the LAN950x datasheet, its bit in the Interrupt Status Register is read-only. There's no other way to clear it than in a separate PHY register: https://www.microchip.com/content/dam/mchp/documents/UNG/ProductDocuments/DataSheets/LAN950x-Data-Sheet-DS00001875D.pdf Consequently, writing "all ones" to the Interrupt Status Register is pointless and can be dropped. Signed-off-by: Lukas Wunner --- drivers/net/usb/smsc95xx.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index edf0492ad489..2cb44d65bbc3 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -572,10 +572,6 @@ static int smsc95xx_link_reset(struct usbnet *dev) unsigned long flags; int ret; - ret = smsc95xx_write_reg(dev, INT_STS, INT_STS_CLEAR_ALL_); - if (ret < 0) - return ret; - spin_lock_irqsave(&pdata->mac_cr_lock, flags); if (pdata->phydev->duplex != DUPLEX_FULL) { pdata->mac_cr &= ~MAC_CR_FDPX_; From patchwork Wed Apr 27 05:48:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828301 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E283BC433FE for ; Wed, 27 Apr 2022 06:01:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357952AbiD0GEt (ORCPT ); Wed, 27 Apr 2022 02:04:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348733AbiD0GEt (ORCPT ); Wed, 27 Apr 2022 02:04:49 -0400 Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [IPv6:2a01:4f8:150:2161:1:b009:f236:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 530D444A1E; Tue, 26 Apr 2022 23:01:39 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 9E867100B0166; Wed, 27 Apr 2022 08:01:35 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 5DADE61ABA99; Wed, 27 Apr 2022 08:01:35 +0200 (CEST) X-Mailbox-Line: From cf64096387a685596b3590452b899618d46de433 Mon Sep 17 00:00:00 2001 Message-Id: In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:03 +0200 Subject: [PATCH net-next 3/7] usbnet: smsc95xx: Don't reset PHY behind PHY driver's back To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org smsc95xx_reset() resets the PHY behind the PHY driver's back, which seems like a bad idea generally. Remove that portion of the function. We're about to use PHY interrupts instead of polling to detect link changes on SMSC LAN95xx chips. Because smsc95xx_reset() is called from usbnet_open(), PHY interrupt settings are lost whenever the net_device is brought up. There are two other callers of smsc95xx_reset(), namely smsc95xx_bind() and smsc95xx_reset_resume(), and both may indeed benefit from a PHY reset. However they already perform one through their calls to phy_connect_direct() and phy_init_hw(). Signed-off-by: Lukas Wunner Cc: Martyn Welch Cc: Gabriel Hojda --- drivers/net/usb/smsc95xx.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 2cb44d65bbc3..6c37c7adde1b 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -887,24 +887,6 @@ static int smsc95xx_reset(struct usbnet *dev) return ret; } - ret = smsc95xx_write_reg(dev, PM_CTRL, PM_CTL_PHY_RST_); - if (ret < 0) - return ret; - - timeout = 0; - do { - msleep(10); - ret = smsc95xx_read_reg(dev, PM_CTRL, &read_buf); - if (ret < 0) - return ret; - timeout++; - } while ((read_buf & PM_CTL_PHY_RST_) && (timeout < 100)); - - if (timeout >= 100) { - netdev_warn(dev->net, "timeout waiting for PHY Reset\n"); - return ret; - } - ret = smsc95xx_set_mac_address(dev); if (ret < 0) return ret; From patchwork Wed Apr 27 05:48:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828308 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 117CFC433F5 for ; Wed, 27 Apr 2022 06:10:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357986AbiD0GNc (ORCPT ); Wed, 27 Apr 2022 02:13:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1357985AbiD0GNa (ORCPT ); Wed, 27 Apr 2022 02:13:30 -0400 X-Greylist: delayed 347 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 26 Apr 2022 23:10:18 PDT Received: from mailout2.hostsharing.net (mailout2.hostsharing.net [IPv6:2a01:37:3000::53df:4ee9:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26703222BD; Tue, 26 Apr 2022 23:10:16 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout2.hostsharing.net (Postfix) with ESMTPS id F07E910321188; Wed, 27 Apr 2022 08:04:25 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id C4D1861ABA99; Wed, 27 Apr 2022 08:04:25 +0200 (CEST) X-Mailbox-Line: From 28fd5a3d53a401cdf8ae0a116108702a46d2c7a2 Mon Sep 17 00:00:00 2001 Message-Id: <28fd5a3d53a401cdf8ae0a116108702a46d2c7a2.1651037513.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:04 +0200 Subject: [PATCH net-next 4/7] usbnet: smsc95xx: Avoid link settings race on interrupt reception To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When a PHY interrupt is signaled, the SMSC LAN95xx driver updates the MAC full duplex mode and PHY flow control registers based on cached data in struct phy_device: smsc95xx_status() # raises EVENT_LINK_RESET usbnet_deferred_kevent() smsc95xx_link_reset() # uses cached data in phydev Simultaneously, phylib polls link status once per second and updates that cached data: phy_state_machine() phy_check_link_status() phy_read_status() lan87xx_read_status() genphy_read_status() # updates cached data in phydev If smsc95xx_link_reset() wins the race against genphy_read_status(), the registers may be updated based on stale data. E.g. if the link was previously down, phydev->duplex is set to DUPLEX_UNKNOWN and that's what smsc95xx_link_reset() will use, even though genphy_read_status() may update it to DUPLEX_FULL afterwards. PHY interrupts are currently only enabled on suspend to trigger wakeup, so the impact of the race is limited, but we're about to enable them perpetually. Avoid the race by delaying execution of smsc95xx_link_reset() until phy_state_machine() has done its job and calls back via smsc95xx_handle_link_change(). Signaling EVENT_LINK_RESET on wakeup is not necessary because phylib picks up link status changes through polling. So drop the declaration of a ->link_reset() callback. Signed-off-by: Lukas Wunner --- drivers/net/usb/smsc95xx.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 6c37c7adde1b..36abfaeae3c6 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -566,7 +566,7 @@ static int smsc95xx_phy_update_flowcontrol(struct usbnet *dev) return smsc95xx_write_reg(dev, AFC_CFG, afc_cfg); } -static int smsc95xx_link_reset(struct usbnet *dev) +static void smsc95xx_mac_update_fullduplex(struct usbnet *dev) { struct smsc95xx_priv *pdata = dev->driver_priv; unsigned long flags; @@ -583,14 +583,14 @@ static int smsc95xx_link_reset(struct usbnet *dev) spin_unlock_irqrestore(&pdata->mac_cr_lock, flags); ret = smsc95xx_write_reg(dev, MAC_CR, pdata->mac_cr); - if (ret < 0) - return ret; + if (ret < 0) { + netdev_warn(dev->net, "Error updating MAC full duplex mode\n"); + return; + } ret = smsc95xx_phy_update_flowcontrol(dev); if (ret < 0) netdev_warn(dev->net, "Error updating PHY flow control\n"); - - return ret; } static void smsc95xx_status(struct usbnet *dev, struct urb *urb) @@ -607,7 +607,7 @@ static void smsc95xx_status(struct usbnet *dev, struct urb *urb) netif_dbg(dev, link, dev->net, "intdata: 0x%08X\n", intdata); if (intdata & INT_ENP_PHY_INT_) - usbnet_defer_kevent(dev, EVENT_LINK_RESET); + ; else netdev_warn(dev->net, "unexpected interrupt, intdata=0x%08X\n", intdata); @@ -1070,6 +1070,7 @@ static void smsc95xx_handle_link_change(struct net_device *net) struct usbnet *dev = netdev_priv(net); phy_print_status(net->phydev); + smsc95xx_mac_update_fullduplex(dev); usbnet_defer_kevent(dev, EVENT_LINK_CHANGE); } @@ -1975,7 +1976,6 @@ static const struct driver_info smsc95xx_info = { .description = "smsc95xx USB 2.0 Ethernet", .bind = smsc95xx_bind, .unbind = smsc95xx_unbind, - .link_reset = smsc95xx_link_reset, .reset = smsc95xx_reset, .check_connect = smsc95xx_start_phy, .stop = smsc95xx_stop, From patchwork Wed Apr 27 05:48:05 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828307 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0441EC433F5 for ; Wed, 27 Apr 2022 06:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233443AbiD0GNH (ORCPT ); Wed, 27 Apr 2022 02:13:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232922AbiD0GNE (ORCPT ); Wed, 27 Apr 2022 02:13:04 -0400 X-Greylist: delayed 496 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 26 Apr 2022 23:09:54 PDT Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [176.9.242.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 164AF67D2B; Tue, 26 Apr 2022 23:09:53 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 5CF4E101952EA; Wed, 27 Apr 2022 08:09:51 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 17DCA61ABA99; Wed, 27 Apr 2022 08:09:51 +0200 (CEST) X-Mailbox-Line: From 276a1b50cf9fcca5168ca2770a863cb56069a277 Mon Sep 17 00:00:00 2001 Message-Id: <276a1b50cf9fcca5168ca2770a863cb56069a277.1651037513.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:05 +0200 Subject: [PATCH net-next 5/7] usbnet: smsc95xx: Forward PHY interrupts to PHY driver to avoid polling To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Link status of SMSC LAN95xx chips is polled once per second, even though they're capable of signaling PHY interrupts through the MAC layer. Forward those interrupts to the PHY driver to avoid polling. Benefits are reduced bus traffic, reduced CPU overhead and quicker interface bringup. Polling was introduced in 2016 by commit d69d16949346 ("usbnet: smsc95xx: fix link detection for disabled autonegotiation"). Back then, the LAN95xx driver neglected to enable the ENERGYON interrupt, hence couldn't detect link-up events when auto-negotiation was disabled. The proper solution would have been to enable the ENERGYON interrupt instead of polling. Since then, PHY handling was moved from the LAN95xx driver to the SMSC PHY driver with commit 05b35e7eb9a1 ("smsc95xx: add phylib support"). That PHY driver is capable of link detection with auto-negotiation disabled because it enables the ENERGYON interrupt. Note that signaling interrupts through the MAC layer not only works with the integrated PHY, but also with an external PHY, provided its interrupt pin is attached to LAN95xx's nPHY_INT pin. In the unlikely event that the interrupt pin of an external PHY is attached to a GPIO of the SoC (or not connected at all), the driver can be amended to retrieve the irq from the PHY's of_node. To forward PHY interrupts to phylib, it is not sufficient to call phy_mac_interrupt(). Instead, the PHY's interrupt handler needs to run so that PHY interrupts are cleared. That's because according to page 119 of the LAN950x datasheet, "The source of this interrupt is a level. The interrupt persists until it is cleared in the PHY." https://www.microchip.com/content/dam/mchp/documents/UNG/ProductDocuments/DataSheets/LAN950x-Data-Sheet-DS00001875D.pdf Therefore, create an IRQ domain with a single IRQ for the PHY. In the future, the IRQ domain may be extended to support the 11 GPIOs on the LAN95xx. Normally the PHY interrupt should be masked until the PHY driver has cleared it. However masking requires a (sleeping) USB transaction and interrupts are received in (non-sleepable) softirq context. I decided not to mask the interrupt at all (by using the dummy_irq_chip's noop ->irq_mask() callback): The USB interrupt endpoint is polled in 1 msec intervals and normally that's sufficient to wake the PHY driver's IRQ thread and have it clear the interrupt. If it does take longer, worst thing that can happen is the IRQ thread is woken again. No big deal. Because PHY interrupts are now perpetually enabled, there's no need to selectively enable them on suspend. So remove all invocations of smsc95xx_enable_phy_wakeup_interrupts(). Signed-off-by: Lukas Wunner Cc: Andre Edich Reviewed-by: Andrew Lunn --- drivers/net/usb/smsc95xx.c | 118 +++++++++++++++++++++---------------- 1 file changed, 66 insertions(+), 52 deletions(-) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 36abfaeae3c6..1d376bad13e5 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -18,6 +18,8 @@ #include #include #include +#include +#include #include #include #include @@ -53,6 +55,9 @@ #define SUSPEND_ALLMODES (SUSPEND_SUSPEND0 | SUSPEND_SUSPEND1 | \ SUSPEND_SUSPEND2 | SUSPEND_SUSPEND3) +#define SMSC95XX_NR_IRQS (1) /* raise to 12 for GPIOs */ +#define PHY_HWIRQ (SMSC95XX_NR_IRQS - 1) + struct smsc95xx_priv { u32 mac_cr; u32 hash_hi; @@ -61,6 +66,9 @@ struct smsc95xx_priv { spinlock_t mac_cr_lock; u8 features; u8 suspend_flags; + struct irq_chip irqchip; + struct irq_domain *irqdomain; + struct fwnode_handle *irqfwnode; struct mii_bus *mdiobus; struct phy_device *phydev; }; @@ -595,6 +603,8 @@ static void smsc95xx_mac_update_fullduplex(struct usbnet *dev) static void smsc95xx_status(struct usbnet *dev, struct urb *urb) { + struct smsc95xx_priv *pdata = dev->driver_priv; + unsigned long flags; u32 intdata; if (urb->actual_length != 4) { @@ -606,11 +616,20 @@ static void smsc95xx_status(struct usbnet *dev, struct urb *urb) intdata = get_unaligned_le32(urb->transfer_buffer); netif_dbg(dev, link, dev->net, "intdata: 0x%08X\n", intdata); + /* USB interrupts are received in softirq (tasklet) context. + * Switch to hardirq context to make genirq code happy. + */ + local_irq_save(flags); + __irq_enter_raw(); + if (intdata & INT_ENP_PHY_INT_) - ; + generic_handle_domain_irq(pdata->irqdomain, PHY_HWIRQ); else netdev_warn(dev->net, "unexpected interrupt, intdata=0x%08X\n", intdata); + + __irq_exit_raw(); + local_irq_restore(flags); } /* Enable or disable Tx & Rx checksum offload engines */ @@ -1078,8 +1097,9 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf) { struct smsc95xx_priv *pdata; bool is_internal_phy; + char usb_path[64]; + int ret, phy_irq; u32 val; - int ret; printk(KERN_INFO SMSC_CHIPNAME " v" SMSC_DRIVER_VERSION "\n"); @@ -1119,10 +1139,38 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf) if (ret) goto free_pdata; + /* create irq domain for use by PHY driver and GPIO consumers */ + usb_make_path(dev->udev, usb_path, sizeof(usb_path)); + pdata->irqfwnode = irq_domain_alloc_named_fwnode(usb_path); + if (!pdata->irqfwnode) { + ret = -ENOMEM; + goto free_pdata; + } + + pdata->irqdomain = irq_domain_create_linear(pdata->irqfwnode, + SMSC95XX_NR_IRQS, + &irq_domain_simple_ops, + pdata); + if (!pdata->irqdomain) { + ret = -ENOMEM; + goto free_irqfwnode; + } + + phy_irq = irq_create_mapping(pdata->irqdomain, PHY_HWIRQ); + if (!phy_irq) { + ret = -ENOENT; + goto remove_irqdomain; + } + + pdata->irqchip = dummy_irq_chip; + pdata->irqchip.name = SMSC_CHIPNAME; + irq_set_chip_and_handler_name(phy_irq, &pdata->irqchip, + handle_simple_irq, "phy"); + pdata->mdiobus = mdiobus_alloc(); if (!pdata->mdiobus) { ret = -ENOMEM; - goto free_pdata; + goto dispose_irq; } ret = smsc95xx_read_reg(dev, HW_CFG, &val); @@ -1155,6 +1203,7 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf) goto unregister_mdio; } + pdata->phydev->irq = phy_irq; pdata->phydev->is_internal = is_internal_phy; /* detect device revision as different features may be available */ @@ -1197,6 +1246,15 @@ static int smsc95xx_bind(struct usbnet *dev, struct usb_interface *intf) free_mdio: mdiobus_free(pdata->mdiobus); +dispose_irq: + irq_dispose_mapping(phy_irq); + +remove_irqdomain: + irq_domain_remove(pdata->irqdomain); + +free_irqfwnode: + irq_domain_free_fwnode(pdata->irqfwnode); + free_pdata: kfree(pdata); return ret; @@ -1209,6 +1267,9 @@ static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf) phy_disconnect(dev->net->phydev); mdiobus_unregister(pdata->mdiobus); mdiobus_free(pdata->mdiobus); + irq_dispose_mapping(irq_find_mapping(pdata->irqdomain, PHY_HWIRQ)); + irq_domain_remove(pdata->irqdomain); + irq_domain_free_fwnode(pdata->irqfwnode); netif_dbg(dev, ifdown, dev->net, "free pdata\n"); kfree(pdata); } @@ -1233,29 +1294,6 @@ static u32 smsc_crc(const u8 *buffer, size_t len, int filter) return crc << ((filter % 2) * 16); } -static int smsc95xx_enable_phy_wakeup_interrupts(struct usbnet *dev, u16 mask) -{ - int ret; - - netdev_dbg(dev->net, "enabling PHY wakeup interrupts\n"); - - /* read to clear */ - ret = smsc95xx_mdio_read_nopm(dev, PHY_INT_SRC); - if (ret < 0) - return ret; - - /* enable interrupt source */ - ret = smsc95xx_mdio_read_nopm(dev, PHY_INT_MASK); - if (ret < 0) - return ret; - - ret |= mask; - - smsc95xx_mdio_write_nopm(dev, PHY_INT_MASK, ret); - - return 0; -} - static int smsc95xx_link_ok_nopm(struct usbnet *dev) { int ret; @@ -1422,7 +1460,6 @@ static int smsc95xx_enter_suspend3(struct usbnet *dev) static int smsc95xx_autosuspend(struct usbnet *dev, u32 link_up) { struct smsc95xx_priv *pdata = dev->driver_priv; - int ret; if (!netif_running(dev->net)) { /* interface is ifconfig down so fully power down hw */ @@ -1441,27 +1478,10 @@ static int smsc95xx_autosuspend(struct usbnet *dev, u32 link_up) } netdev_dbg(dev->net, "autosuspend entering SUSPEND1\n"); - - /* enable PHY wakeup events for if cable is attached */ - ret = smsc95xx_enable_phy_wakeup_interrupts(dev, - PHY_INT_MASK_ANEG_COMP_); - if (ret < 0) { - netdev_warn(dev->net, "error enabling PHY wakeup ints\n"); - return ret; - } - netdev_info(dev->net, "entering SUSPEND1 mode\n"); return smsc95xx_enter_suspend1(dev); } - /* enable PHY wakeup events so we remote wakeup if cable is pulled */ - ret = smsc95xx_enable_phy_wakeup_interrupts(dev, - PHY_INT_MASK_LINK_DOWN_); - if (ret < 0) { - netdev_warn(dev->net, "error enabling PHY wakeup ints\n"); - return ret; - } - netdev_dbg(dev->net, "autosuspend entering SUSPEND3\n"); return smsc95xx_enter_suspend3(dev); } @@ -1527,13 +1547,6 @@ static int smsc95xx_suspend(struct usb_interface *intf, pm_message_t message) } if (pdata->wolopts & WAKE_PHY) { - ret = smsc95xx_enable_phy_wakeup_interrupts(dev, - (PHY_INT_MASK_ANEG_COMP_ | PHY_INT_MASK_LINK_DOWN_)); - if (ret < 0) { - netdev_warn(dev->net, "error enabling PHY wakeup ints\n"); - goto done; - } - /* if link is down then configure EDPD and enter SUSPEND1, * otherwise enter SUSPEND0 below */ @@ -1767,11 +1780,12 @@ static int smsc95xx_resume(struct usb_interface *intf) return ret; } + phy_init_hw(pdata->phydev); + ret = usbnet_resume(intf); if (ret < 0) netdev_warn(dev->net, "usbnet_resume error\n"); - phy_init_hw(pdata->phydev); return ret; } From patchwork Wed Apr 27 05:48:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828309 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A573C433EF for ; Wed, 27 Apr 2022 06:12:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343513AbiD0GPm (ORCPT ); Wed, 27 Apr 2022 02:15:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229930AbiD0GPk (ORCPT ); Wed, 27 Apr 2022 02:15:40 -0400 Received: from mailout2.hostsharing.net (mailout2.hostsharing.net [IPv6:2a01:37:3000::53df:4ee9:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4065275D4; Tue, 26 Apr 2022 23:12:30 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout2.hostsharing.net (Postfix) with ESMTPS id 3C06C10321188; Wed, 27 Apr 2022 08:12:29 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 081F661ABA99; Wed, 27 Apr 2022 08:12:28 +0200 (CEST) X-Mailbox-Line: From 7603f74ddc32bbaa55e9f1bea5d4024b6e376035 Mon Sep 17 00:00:00 2001 Message-Id: <7603f74ddc32bbaa55e9f1bea5d4024b6e376035.1651037513.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:06 +0200 Subject: [PATCH net-next 6/7] net: phy: smsc: Cache interrupt mask To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Cache the interrupt mask to avoid re-reading it from the PHY upon every interrupt. The PHY may be located on a USB device, so the additional read may unnecessarily increase interrupt overhead and latency. Signed-off-by: Lukas Wunner --- drivers/net/phy/smsc.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c index d8cac02a79b9..a521d48b22a7 100644 --- a/drivers/net/phy/smsc.c +++ b/drivers/net/phy/smsc.c @@ -44,6 +44,7 @@ static struct smsc_hw_stat smsc_hw_stats[] = { }; struct smsc_phy_priv { + u16 intmask; bool energy_enable; struct clk *refclk; }; @@ -58,7 +59,6 @@ static int smsc_phy_ack_interrupt(struct phy_device *phydev) static int smsc_phy_config_intr(struct phy_device *phydev) { struct smsc_phy_priv *priv = phydev->priv; - u16 intmask = 0; int rc; if (phydev->interrupts == PHY_INTERRUPT_ENABLED) { @@ -66,12 +66,15 @@ static int smsc_phy_config_intr(struct phy_device *phydev) if (rc) return rc; - intmask = MII_LAN83C185_ISF_INT4 | MII_LAN83C185_ISF_INT6; + priv->intmask = MII_LAN83C185_ISF_INT4 | MII_LAN83C185_ISF_INT6; if (priv->energy_enable) - intmask |= MII_LAN83C185_ISF_INT7; - rc = phy_write(phydev, MII_LAN83C185_IM, intmask); + priv->intmask |= MII_LAN83C185_ISF_INT7; + + rc = phy_write(phydev, MII_LAN83C185_IM, priv->intmask); } else { - rc = phy_write(phydev, MII_LAN83C185_IM, intmask); + priv->intmask = 0; + + rc = phy_write(phydev, MII_LAN83C185_IM, 0); if (rc) return rc; @@ -83,13 +86,8 @@ static int smsc_phy_config_intr(struct phy_device *phydev) static irqreturn_t smsc_phy_handle_interrupt(struct phy_device *phydev) { - int irq_status, irq_enabled; - - irq_enabled = phy_read(phydev, MII_LAN83C185_IM); - if (irq_enabled < 0) { - phy_error(phydev); - return IRQ_NONE; - } + struct smsc_phy_priv *priv = phydev->priv; + int irq_status; irq_status = phy_read(phydev, MII_LAN83C185_ISF); if (irq_status < 0) { @@ -97,7 +95,7 @@ static irqreturn_t smsc_phy_handle_interrupt(struct phy_device *phydev) return IRQ_NONE; } - if (!(irq_status & irq_enabled)) + if (!(irq_status & priv->intmask)) return IRQ_NONE; phy_trigger_machine(phydev); From patchwork Wed Apr 27 05:48:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 12828318 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E666C433EF for ; Wed, 27 Apr 2022 06:14:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358020AbiD0GRq (ORCPT ); Wed, 27 Apr 2022 02:17:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348979AbiD0GRp (ORCPT ); Wed, 27 Apr 2022 02:17:45 -0400 Received: from mailout3.hostsharing.net (mailout3.hostsharing.net [176.9.242.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22FED72E1A; Tue, 26 Apr 2022 23:14:34 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS DV RSA Mixed SHA256 2020 CA-1" (verified OK)) by mailout3.hostsharing.net (Postfix) with ESMTPS id 42DBA101952EA; Wed, 27 Apr 2022 08:14:33 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 05C486151168; Wed, 27 Apr 2022 08:14:32 +0200 (CEST) X-Mailbox-Line: From 62b8375ae008035bcaa85c348ea4aa80c519bb07 Mon Sep 17 00:00:00 2001 Message-Id: <62b8375ae008035bcaa85c348ea4aa80c519bb07.1651037513.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Wed, 27 Apr 2022 07:48:07 +0200 Subject: [PATCH net-next 7/7] net: phy: smsc: Cope with hot-removal in interrupt handler To: Steve Glendinning , UNGLinuxDriver@microchip.com, Oliver Neukum , "David S. Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-usb@vger.kernel.org, Andre Edich , Oleksij Rempel , Martyn Welch , Gabriel Hojda , Christoph Fritz , Lino Sanfilippo , Philipp Rosenberger , Heiner Kallweit , Andrew Lunn , Russell King Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org If reading the Interrupt Source Flag register fails with -ENODEV, then the PHY has been hot-removed and the correct response is to bail out instead of throwing a WARN splat and attempting to suspend the PHY. The PHY should be stopped in due course anyway as the kernel asynchronously tears down the device. Signed-off-by: Lukas Wunner --- drivers/net/phy/smsc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c index a521d48b22a7..35bff7fd234c 100644 --- a/drivers/net/phy/smsc.c +++ b/drivers/net/phy/smsc.c @@ -91,7 +91,9 @@ static irqreturn_t smsc_phy_handle_interrupt(struct phy_device *phydev) irq_status = phy_read(phydev, MII_LAN83C185_ISF); if (irq_status < 0) { - phy_error(phydev); + if (irq_status != -ENODEV) + phy_error(phydev); + return IRQ_NONE; }