| Message ID | 20180520134846.31046-2-digetx@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <digetx@gmail.com> > --- > 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; >
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;
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@gmail.com> --- drivers/staging/media/tegra-vde/tegra-vde.c | 42 +++++++++++++++++++-- 1 file changed, 38 insertions(+), 4 deletions(-)