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 <digetx@xxxxxxxxx> --- 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) { + 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; -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html