From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wr0-f194.google.com ([209.85.128.194]:43193 "EHLO mail-wr0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752095AbeEZO24 (ORCPT ); Sat, 26 May 2018 10:28:56 -0400 From: Dmitry Osipenko To: Hans Verkuil , Mauro Carvalho Chehab , Thierry Reding Cc: linux-tegra@vger.kernel.org, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] media: staging: tegra-vde: Reset memory client Date: Sat, 26 May 2018 17:27:55 +0300 Message-Id: <20180526142755.22966-1-digetx@gmail.com> Sender: linux-media-owner@vger.kernel.org List-ID: DMA requests must be blocked before resetting VDE HW, otherwise it is possible to get a memory corruption or a machine hang. Use the reset control provided by the Memory Controller to block DMA before resetting the VDE HW. Signed-off-by: Dmitry Osipenko --- Changelog: v2: - Reset HW even if Memory Client resetting fails. drivers/staging/media/tegra-vde/tegra-vde.c | 35 +++++++++++++++++++-- 1 file changed, 33 insertions(+), 2 deletions(-) diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/tegra-vde.c index 90177a59b97c..6f06061a40d9 100644 --- a/drivers/staging/media/tegra-vde/tegra-vde.c +++ b/drivers/staging/media/tegra-vde/tegra-vde.c @@ -73,6 +73,7 @@ struct tegra_vde { struct mutex lock; struct miscdevice miscdev; struct reset_control *rst; + struct reset_control *rst_mc; struct gen_pool *iram_pool; struct completion decode_completion; struct clk *clk; @@ -850,9 +851,23 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, * We rely on the VDE registers reset value, otherwise VDE * causes bus lockup. */ + ret = reset_control_assert(vde->rst_mc); + if (ret) { + dev_err(dev, "DEC start: Failed to assert MC reset: %d\n", + ret); + goto put_runtime_pm; + } + ret = reset_control_reset(vde->rst); if (ret) { - dev_err(dev, "Failed to reset HW: %d\n", ret); + dev_err(dev, "DEC start: Failed to reset HW: %d\n", ret); + goto put_runtime_pm; + } + + ret = reset_control_deassert(vde->rst_mc); + if (ret) { + dev_err(dev, "DEC start: Failed to deassert MC reset: %d\n", + ret); goto put_runtime_pm; } @@ -880,9 +895,18 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, ret = timeout; } + /* + * At first reset memory client to avoid resetting VDE HW in the + * middle of DMA which could result into memory corruption or hang + * the whole system. + */ + err = reset_control_assert(vde->rst_mc); + if (err) + dev_err(dev, "DEC end: Failed to assert MC reset: %d\n", err); + err = reset_control_assert(vde->rst); if (err) - dev_err(dev, "Failed to assert HW reset: %d\n", err); + dev_err(dev, "DEC end: Failed to assert HW reset: %d\n", err); put_runtime_pm: pm_runtime_mark_last_busy(dev); @@ -1074,6 +1098,13 @@ static int tegra_vde_probe(struct platform_device *pdev) return err; } + vde->rst_mc = devm_reset_control_get_optional(dev, "mc"); + if (IS_ERR(vde->rst_mc)) { + err = PTR_ERR(vde->rst_mc); + dev_err(dev, "Could not get MC reset %d\n", err); + return err; + } + irq = platform_get_irq_byname(pdev, "sync-token"); if (irq < 0) return irq; -- 2.17.0