From patchwork Tue Dec 13 15:07:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bartosz Golaszewski X-Patchwork-Id: 87897 Delivered-To: patch@linaro.org Received: by 10.140.20.101 with SMTP id 92csp2251475qgi; Tue, 13 Dec 2016 07:08:04 -0800 (PST) X-Received: by 10.98.11.198 with SMTP id 67mr101830333pfl.90.1481641684654; Tue, 13 Dec 2016 07:08:04 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 20si48191830pgk.218.2016.12.13.07.08.03; Tue, 13 Dec 2016 07:08:04 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@baylibre-com.20150623.gappssmtp.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933633AbcLMPHr (ORCPT + 25 others); Tue, 13 Dec 2016 10:07:47 -0500 Received: from mail-wm0-f42.google.com ([74.125.82.42]:38269 "EHLO mail-wm0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932346AbcLMPHm (ORCPT ); Tue, 13 Dec 2016 10:07:42 -0500 Received: by mail-wm0-f42.google.com with SMTP id f82so124211943wmf.1 for ; Tue, 13 Dec 2016 07:07:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=IbzubiQ5SrYCssm/E906keWrIrEFwuVNd8xyNOhlZdg=; b=RFfNvGLdj3k4JJVxojUsaxLvS4wW4FVlt484OKK9zfFReJ/LCAYX/LaZ5j0v1918tc tM3+ZBK35jr2FxmcDs4qRoDLSadFgluuHvix3/TAl2QVssA9L0JR4zU5cURw3fYFngs6 6NpQqJx0I2UXDg69dAXZnsHieBRaPvuH4rBqZ6U/f9le02Q8ZDZehr8zuFaTJg/W2IiR qHVJvDJNoXdlYsaQN5dbeMAry6XnoffHJ09gzkZd6tivj0DrhmqzcbdGfB7WHiik7asC Q40wz2chLVJuWt6S1sjW6xNq6BgGwp+wY82heGpzW7BRBZ6VKRNfeYjslWrvCMJsJdaG s/ng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=IbzubiQ5SrYCssm/E906keWrIrEFwuVNd8xyNOhlZdg=; b=G09xl1CJ/PnQsQWo8BIk6qQH0IqS2uhhwpr95Xxuj6HwltClequlSImv6P/46xzNvc o9pSmgczlaw+bd/poXgrIznoy4lOvx/Ntr0pGyHnb0Iou/X4Kh4k3sunVRfHACVGmEc1 +MA93w5iv3hTTBt/9QexBDL6CpVvTq6ilFiif+FI8WYUV9WS8fx3GixRXQ+FIi2hEpeA 7VWvVD4/dacZaXkobLtrwxwNm+eKEDgIIH2PI0YU37fJ4lC1xDkiXbRhsUfS/A6r3Gdv ZVXCtBS1SR7ZJyvzfkhs6zB6PLoH3X6J04UzZscc3Bj+B5Y87tWmwuA/lGdDvC9eDGJk /6HQ== X-Gm-Message-State: AKaTC03g83t7WuBC2NA/qGKcVQbuk70T68EDuSDKtUteRvNWwHsheU6SMJknM+GWiAUrK8fn X-Received: by 10.28.182.70 with SMTP id g67mr3331701wmf.90.1481641661124; Tue, 13 Dec 2016 07:07:41 -0800 (PST) Received: from localhost.localdomain ([90.63.244.31]) by smtp.gmail.com with ESMTPSA id n5sm3040660wmf.0.2016.12.13.07.07.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 13 Dec 2016 07:07:40 -0800 (PST) From: Bartosz Golaszewski To: Jyri Sarha , Tomi Valkeinen , David Airlie , Kevin Hilman , Michael Turquette , Sekhar Nori Cc: LKML , linux-drm , Peter Ujfalusi , arm-soc , Bartosz Golaszewski Subject: [PATCH] drm: tilcdc: simplify the recovery from sync lost error on rev1 Date: Tue, 13 Dec 2016 16:07:36 +0100 Message-Id: <1481641656-25227-1-git-send-email-bgolaszewski@baylibre.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Revision 2 of LCDC suffers from an issue where a SYNC_LOST error caused by limited memory bandwidth may leave the picture shifted a couple pixels to the right. This issue has not been observed on revision 1, while the recovery mechanism introduces a different issue, where the END_OF_FRAME interrupt doesn't fire while drm is waiting for vblanks. On rev1: recover from sync lost errors by simply clearing the RASTER_ENABLE bit in the RASTER_CTRL register and re-enabling it again as is suggested by the datasheet. Signed-off-by: Bartosz Golaszewski --- drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) -- 2.9.3 diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 9942b05..70e57a7 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -921,17 +921,23 @@ irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc) dev_err_ratelimited(dev->dev, "%s(0x%08x): Sync lost", __func__, stat); tilcdc_crtc->frame_intact = false; - if (tilcdc_crtc->sync_lost_count++ > - SYNC_LOST_COUNT_LIMIT) { - dev_err(dev->dev, "%s(0x%08x): Sync lost flood detected, recovering", __func__, stat); - queue_work(system_wq, &tilcdc_crtc->recover_work); - if (priv->rev == 1) - tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, - LCDC_V1_SYNC_LOST_INT_ENA); - else + if (priv->rev == 1) { + tilcdc_clear(dev, + LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE); + tilcdc_set(dev, + LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE); + } else { + if (tilcdc_crtc->sync_lost_count++ > + SYNC_LOST_COUNT_LIMIT) { + dev_err(dev->dev, + "%s(0x%08x): Sync lost flood detected, recovering", + __func__, stat); + queue_work(system_wq, + &tilcdc_crtc->recover_work); tilcdc_write(dev, LCDC_INT_ENABLE_CLR_REG, LCDC_SYNC_LOST); - tilcdc_crtc->sync_lost_count = 0; + tilcdc_crtc->sync_lost_count = 0; + } } }