From patchwork Mon Dec 9 08:27:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 11278571 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4BCDB1864 for ; Mon, 9 Dec 2019 08:27:25 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 300CF20663 for ; Mon, 9 Dec 2019 08:27:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 300CF20663 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F40596E09C; Mon, 9 Dec 2019 08:27:22 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from lelv0143.ext.ti.com (lelv0143.ext.ti.com [198.47.23.248]) by gabe.freedesktop.org (Postfix) with ESMTPS id A879B6E09C for ; Mon, 9 Dec 2019 08:27:21 +0000 (UTC) Received: from lelv0265.itg.ti.com ([10.180.67.224]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id xB98RGUZ008665; Mon, 9 Dec 2019 02:27:16 -0600 Received: from DFLE114.ent.ti.com (dfle114.ent.ti.com [10.64.6.35]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id xB98RGNW090938 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 9 Dec 2019 02:27:16 -0600 Received: from DFLE106.ent.ti.com (10.64.6.27) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Mon, 9 Dec 2019 02:27:15 -0600 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE106.ent.ti.com (10.64.6.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Mon, 9 Dec 2019 02:27:15 -0600 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id xB98RDnC078329; Mon, 9 Dec 2019 02:27:13 -0600 From: Tomi Valkeinen To: , Andrey Smirnov , Andrzej Hajda , Laurent Pinchart , Lucas Stach , Andrey Gusakov Subject: [PATCH] drm/bridge: tc358767: fix poll timeouts Date: Mon, 9 Dec 2019 10:27:07 +0200 Message-ID: <20191209082707.24531-1-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1575880036; bh=gr+id/kVHkGklUKISNfvxtpwWhp0KZPGQr4zeHj1NHo=; h=From:To:CC:Subject:Date; b=AvTKbmcknRyE0CPyu92wFYbwqYO+gfgI6bDdIJxkZM1ESlB+0Z/dAdPwTvIsrBz39 0UBMxIk1Z/6KS8/W6EN8c53g6X1DnIkgX8v+LccrYuvvwCDzwbLVM2vjBzVDoaVrBf sG2uEz3FrJievtdaztsGpyy6xb0989Dh05UaQ660= X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tomi Valkeinen , Jyri Sarha Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Link training fails with: Link training timeout waiting for LT_LOOPDONE! main link enable error: -110 This is caused by too tight timeouts, which were changed recently in aa92213f388b ("drm/bridge: tc358767: Simplify polling in tc_link_training()"). With a quick glance, the commit does not change the timeouts. However, the method of delaying/sleeping is different, and as the timeout in the previous implementation was not explicit, the new version in practice has much tighter timeout. The same change was made to other parts in the driver, but the link training timeout is the only one I have seen causing issues. Nevertheless, 1 us sleep is not very sane, and the timeouts look pretty tight, so lets fix all the timeouts. One exception was the aux busy poll, where the poll sleep was much longer than necessary (or optimal). I measured the times on my setup, and now the sleep times are set to such values that they result in multiple loops, but not too many (say, 5-10 loops). The timeouts were all increased to 100ms, which should be more than enough for all of these, but in case of bad errors, shouldn't stop the driver as multi-second timeouts could do. Signed-off-by: Tomi Valkeinen Fixes: aa92213f388b ("drm/bridge: tc358767: Simplify polling in tc_link_training()") Tested-by: Andrey Smirnov Reviewed-by: Neil Armstrong --- drivers/gpu/drm/bridge/tc358767.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 8a8d605021f0..0454675a44cb 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -294,7 +294,7 @@ static inline int tc_poll_timeout(struct tc_data *tc, unsigned int addr, static int tc_aux_wait_busy(struct tc_data *tc) { - return tc_poll_timeout(tc, DP0_AUXSTATUS, AUX_BUSY, 0, 1000, 100000); + return tc_poll_timeout(tc, DP0_AUXSTATUS, AUX_BUSY, 0, 100, 100000); } static int tc_aux_write_data(struct tc_data *tc, const void *data, @@ -637,7 +637,7 @@ static int tc_aux_link_setup(struct tc_data *tc) if (ret) goto err; - ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 1, 1000); + ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 100, 100000); if (ret == -ETIMEDOUT) { dev_err(tc->dev, "Timeout waiting for PHY to become ready"); return ret; @@ -861,7 +861,7 @@ static int tc_wait_link_training(struct tc_data *tc) int ret; ret = tc_poll_timeout(tc, DP0_LTSTAT, LT_LOOPDONE, - LT_LOOPDONE, 1, 1000); + LT_LOOPDONE, 500, 100000); if (ret) { dev_err(tc->dev, "Link training timeout waiting for LT_LOOPDONE!\n"); return ret; @@ -934,7 +934,7 @@ static int tc_main_link_enable(struct tc_data *tc) dp_phy_ctrl &= ~(DP_PHY_RST | PHY_M1_RST | PHY_M0_RST); ret = regmap_write(tc->regmap, DP_PHY_CTRL, dp_phy_ctrl); - ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 1, 1000); + ret = tc_poll_timeout(tc, DP_PHY_CTRL, PHY_RDY, PHY_RDY, 500, 100000); if (ret) { dev_err(dev, "timeout waiting for phy become ready"); return ret;