From patchwork Tue Mar 19 22:51:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 13597112 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 53A75C54E68 for ; Tue, 19 Mar 2024 22:52:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HKfen1j5iFkM3AfZogPzfZ2hEl470z8K8CJo9rGqApg=; b=isKh75zE4Ai1gl VkvKUbRjgt/V3UfUIyhT63ijkPuwrqrgoFeckuiDFkNfVChU1/NqqZql2bitGG2xSLmJQHn7cmucv DLpMediPHVlR277E8ItQ2qjZfWWtojm0ehhBQMIOYaaHbMx327hjT1xQ2Og85rch/87Vi6ppjYls7 zLiHUvSWw31ls5fLE8Ak0BF4A9yQbaZpeOE/xmTbBMGxurAJkIyl+Jfq/48WsgGvfroeoUmRdtNP8 M9goRrxzfV99p9Mmo+4ZCFJLn3hUAFb6kYWYhEb8bk1y5jDV++IjGNoHtDiX3Xe9xakLKhxkv+IT9 Mu2ylHm9WVf2z5wLkOGQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmiJX-0000000EVgB-1dAW; Tue, 19 Mar 2024 22:52:11 +0000 Received: from out-189.mta0.migadu.com ([2001:41d0:1004:224b::bd]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmiJA-0000000EVOr-0sJo for linux-arm-kernel@lists.infradead.org; Tue, 19 Mar 2024 22:51:51 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1710888706; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IyA1pp/Og9a0uR7KxvRUeBHWPGqjk6cC2yqaXPFBa2g=; b=OMzjesS1g9SgReAooXmXRO+rEeJVZZbO6Fw4R7WVyiz+Aa9xbBeLmtWXnAt5W4EGrFHIuc ZcKCCp5Hx1RcmuU3fc+KSCRCbJ+N7vMEMGQiXQsM7vz/qA90NBCUbHwtOSe5SWcia4bzV1 DhIc4OJlMAb1g4JIKmfOCdsLzRRijLI= From: Sean Anderson To: Laurent Pinchart , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , dri-devel@lists.freedesktop.org Cc: Michal Simek , David Airlie , linux-kernel@vger.kernel.org, Daniel Vetter , linux-arm-kernel@lists.infradead.org, Sean Anderson Subject: [PATCH v2 5/8] drm: zynqmp_dp: Don't retrain the link in our IRQ Date: Tue, 19 Mar 2024 18:51:18 -0400 Message-Id: <20240319225122.3048400-6-sean.anderson@linux.dev> In-Reply-To: <20240319225122.3048400-1-sean.anderson@linux.dev> References: <20240319225122.3048400-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240319_155148_417294_C3ABE3E5 X-CRM114-Status: GOOD ( 16.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Retraining the link can take a while, and might involve waiting for DPCD reads/writes to complete. This is inappropriate for an IRQ handler. Just schedule this work for later completion. This is racy, but will be fixed in the next commit. Signed-off-by: Sean Anderson --- Actually, on second look this IRQ is threaded. So why do we have a workqueue for HPD events? Maybe we should make it unthreaded? Changes in v2: - Document hpd_irq_work - Split this off from the lcoking changes drivers/gpu/drm/xlnx/zynqmp_dp.c | 43 ++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index f1834c8e3c02..f3fcdbf662fa 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -287,6 +287,7 @@ struct zynqmp_dp_config { * @phy: PHY handles for DP lanes * @num_lanes: number of enabled phy lanes * @hpd_work: hot plug detection worker + * @hpd_irq_work: hot plug detection IRQ worker * @status: connection status * @enabled: flag to indicate if the device is enabled * @dpcd: DP configuration data from currently connected sink device @@ -298,6 +299,7 @@ struct zynqmp_dp { struct drm_dp_aux aux; struct drm_bridge bridge; struct delayed_work hpd_work; + struct delayed_work hpd_irq_work; struct drm_bridge *next_bridge; struct device *dev; @@ -1611,6 +1613,27 @@ static void zynqmp_dp_hpd_work_func(struct work_struct *work) drm_bridge_hpd_notify(&dp->bridge, status); } +static void zynqmp_dp_hpd_irq_work_func(struct work_struct *work) +{ + struct zynqmp_dp *dp = container_of(work, struct zynqmp_dp, + hpd_irq_work.work); + u8 status[DP_LINK_STATUS_SIZE + 2]; + int err; + + err = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status, + DP_LINK_STATUS_SIZE + 2); + if (err < 0) { + dev_dbg_ratelimited(dp->dev, + "could not read sink status: %d\n", err); + } else { + if (status[4] & DP_LINK_STATUS_UPDATED || + !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) || + !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) { + zynqmp_dp_train_loop(dp); + } + } +} + static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data) { struct zynqmp_dp *dp = (struct zynqmp_dp *)data; @@ -1635,23 +1658,9 @@ static irqreturn_t zynqmp_dp_irq_handler(int irq, void *data) if (status & ZYNQMP_DP_INT_HPD_EVENT) schedule_delayed_work(&dp->hpd_work, 0); - if (status & ZYNQMP_DP_INT_HPD_IRQ) { - int ret; - u8 status[DP_LINK_STATUS_SIZE + 2]; + if (status & ZYNQMP_DP_INT_HPD_IRQ) + schedule_delayed_work(&dp->hpd_irq_work, 0); - ret = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status, - DP_LINK_STATUS_SIZE + 2); - if (ret < 0) - goto handled; - - if (status[4] & DP_LINK_STATUS_UPDATED || - !drm_dp_clock_recovery_ok(&status[2], dp->mode.lane_cnt) || - !drm_dp_channel_eq_ok(&status[2], dp->mode.lane_cnt)) { - zynqmp_dp_train_loop(dp); - } - } - -handled: return IRQ_HANDLED; } @@ -1676,6 +1685,7 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub) dp->status = connector_status_disconnected; INIT_DELAYED_WORK(&dp->hpd_work, zynqmp_dp_hpd_work_func); + INIT_DELAYED_WORK(&dp->hpd_irq_work, zynqmp_dp_hpd_irq_work_func); /* Acquire all resources (IOMEM, IRQ and PHYs). */ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dp"); @@ -1775,6 +1785,7 @@ void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub) zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, ZYNQMP_DP_INT_ALL); disable_irq(dp->irq); + cancel_delayed_work_sync(&dp->hpd_irq_work); cancel_delayed_work_sync(&dp->hpd_work); zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 0);