From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031696AbeEZKDI (ORCPT ); Sat, 26 May 2018 06:03:08 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:51194 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031487AbeEZKDF (ORCPT ); Sat, 26 May 2018 06:03:05 -0400 X-Google-Smtp-Source: AB8JxZqaemJKvaRBlaKNQ7tbYSksyDnTA5TlOmiESmtsE9MbkEE2DSh1Yt1c0nzyuM4Qpu2edpeXCA== Subject: Re: [PATCH v1] media: staging: tegra-vde: Reset memory client From: Dmitry Osipenko To: Hans Verkuil , Mauro Carvalho Chehab , Thierry Reding , Jonathan Hunter Cc: linux-tegra@vger.kernel.org, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org References: <20180520134846.31046-1-digetx@gmail.com> <20180520134846.31046-2-digetx@gmail.com> Openpgp: preference=signencrypt Autocrypt: addr=digetx@gmail.com; prefer-encrypt=mutual; keydata= xsBNBFpX5TwBCADQhg+lBnTunWSPbP5I+rM9q6EKPm5fu2RbqyVAh/W3fRvLyghdb58Yrmjm KpDYUhBIZvAQoFLEL1IPAgJBtmPvemO1XUGPxfYNh/3BlcDFBAgERrI3BfA/6pk7SAFn8u84 p+J1TW4rrPYcusfs44abJrn8CH0GZKt2AZIsGbGQ79O2HHXKHr9V95ZEPWH5AR0UtL6wxg6o O56UNG3rIzSL5getRDQW3yCtjcqM44mz6GPhSE2sxNgqureAbnzvr4/93ndOHtQUXPzzTrYB z/WqLGhPdx5Ouzn0Q0kSVCQiqeExlcQ7i7aKRRrELz/5/IXbCo2O+53twlX8xOps9iMfABEB AAHNIkRtaXRyeSBPc2lwZW5rbyA8ZGlnZXR4QGdtYWlsLmNvbT7CwJQEEwEIAD4WIQSczHcO 3uc4K1eb3yvTNNaPsNRzvAUCWlflPAIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIX gAAKCRDTNNaPsNRzvFjTCACqAh1M9/YPq73/ai5h2ExDquTgJnjegL8KL2yHL3G+XINwzN5E nPI7esoYm+zVWDJbv3UuRqylpookLNSRA01yyvkaMcipB/B128UnqmUiGRqezj9QE20yIauo uHRuwHPE2q+UkfUhRX9iuOaEyQtZDiCa0myMjmRkJ+Z8ZetclEPG8dYZu47w04phuMlu1QAt a0gkZOaMKvXgj21ushALS6nYnvm7HiIPQXfnEXThartatRvFdmbG4PCn0IoICkQBizwJtXrL HEjELIFap0M8krVJlUoZTFaZnaZkGpUDWikeFtAuie2KuIxmVBYPM4X7pM3eP3AVvIPGS7EE UUFuzsBNBFpX5TwBCADFNDou220thijaLLGaQsebWjzc/gPRxMixIpk856MRyRaQin+IbGD6 YskMb5ZSD3nS88LIKNfY4MMH0LwfYztI++ICG2vdFLkbBt78E+LqEa+kZ9072l4W5KO3mWQo +jMfxXbpgGlc7iuEReDgl8iyZ27r51kSW665CYvvu2YJhLqgdj6QM1lN2D1UnhEhkkU+pRAj 1rJVOxdfJaQNQS4+204p3TrURovzNGkN/brqakpNIcqGOAGQqb8F0tuwwuP7ERq/BzDNkbdr qJOrVC/wkHRq1jfabQczWKf8MwYOvivR3HY8d3CpSQxmUXDtdOWfg0XGm1dxYnVfqPjuJaZt ABEBAAHCwHwEGAEIACYWIQSczHcO3uc4K1eb3yvTNNaPsNRzvAUCWlflPAIbDAUJA8JnAAAK CRDTNNaPsNRzvJzuB/9d+sxcwHbO8ZDcgaLX9N+bXFqN9fIRVmBUyWa+qqTSREA4uVAtYcRT lfPE2OQ7aMFxaYPwo+/z5SLpu8HcEhN/FG9uIkfYwK0mdCO0vgvlfvBJm4VHe7C6vyAeEPJQ DKbBvdgeqFqO+PsLkk2sawF/9sontMJ5iFfjNDj4UeAo4VsdlduTBZv5hHFvIbv/p7jKH6OT 90FsgUSVbShh7SH5OzAcgqSy4kxuS1AHizWo6P3f9vei987LZWTyhuEuhJsOfivDsjKIq7qQ c5eR+JJtyLEA0Jt4cQGhpzHtWB0yB3XxXzHVa4QUp00BNVWyiJ/t9JHT4S5mdyLfcKm7ddc9 Message-ID: <24810d9d-eede-f9dd-1dbe-e757cfa2e191@gmail.com> Date: Sat, 26 May 2018 13:03:01 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180520134846.31046-2-digetx@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20.05.2018 16:48, Dmitry Osipenko wrote: > 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 > --- > drivers/staging/media/tegra-vde/tegra-vde.c | 42 +++++++++++++++++++-- > 1 file changed, 38 insertions(+), 4 deletions(-) > > diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/tegra-vde.c > index 90177a59b97c..6dd3bf4481be 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 +895,21 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, > ret = timeout; > } > > - err = reset_control_assert(vde->rst); > - if (err) > - dev_err(dev, "Failed to assert HW reset: %d\n", err); > + /* > + * 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) { It occurred to me that there is no need to skip the HW reset if MC resetting fails. I'll make V2 to change that. > + err = reset_control_assert(vde->rst); > + if (err) > + dev_err(dev, > + "DEC end: Failed to assert HW reset: %d\n", > + err); > + } else { > + dev_err(dev, "DEC end: Failed to assert MC reset: %d\n", err); > + } > > put_runtime_pm: > pm_runtime_mark_last_busy(dev); > @@ -1074,6 +1101,13 @@ 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; >