Re: [PATCH AUTOSEL 5.2 51/59] drm/exynos: fix missing decrement of retry counter
On Wed, Aug 07, 2019 at 08:49:52AM +, David Laight wrote: From: Sasha Levin Sent: 06 August 2019 22:33 From: Colin Ian King [ Upstream commit 1bbbab097a05276e312dd2462791d32b21ceb1ee ] Currently the retry counter is not being decremented, leading to a potential infinite spin if the scalar_reads don't change state. Addresses-Coverity: ("Infinite loop") Fixes: 280e54c9f614 ("drm/exynos: scaler: Reset hardware before starting the operation") Signed-off-by: Colin Ian King Signed-off-by: Inki Dae Signed-off-by: Sasha Levin --- drivers/gpu/drm/exynos/exynos_drm_scaler.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_scaler.c b/drivers/gpu/drm/exynos/exynos_drm_scaler.c index ec9c1b7d31033..8989f8af716b7 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c +++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c @@ -94,12 +94,12 @@ static inline int scaler_reset(struct scaler_context *scaler) scaler_write(SCALER_CFG_SOFT_RESET, SCALER_CFG); do { cpu_relax(); - } while (retry > 1 && + } while (--retry > 1 && scaler_read(SCALER_CFG) & SCALER_CFG_SOFT_RESET); do { cpu_relax(); scaler_write(1, SCALER_INT_EN); - } while (retry > 0 && scaler_read(SCALER_INT_EN) != 1); + } while (--retry > 0 && scaler_read(SCALER_INT_EN) != 1); return retry ? 0 : -EIO; If the first loop hits the retry limit the second loop won't be right and the final return value will be 0. This looks like an upstream problem as well, no? -- Thanks, Sasha ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
RE: [PATCH AUTOSEL 5.2 51/59] drm/exynos: fix missing decrement of retry counter
From: Sasha Levin > Sent: 06 August 2019 22:33 > > From: Colin Ian King > > [ Upstream commit 1bbbab097a05276e312dd2462791d32b21ceb1ee ] > > Currently the retry counter is not being decremented, leading to a > potential infinite spin if the scalar_reads don't change state. > > Addresses-Coverity: ("Infinite loop") > Fixes: 280e54c9f614 ("drm/exynos: scaler: Reset hardware before starting the > operation") > Signed-off-by: Colin Ian King > Signed-off-by: Inki Dae > Signed-off-by: Sasha Levin > --- > drivers/gpu/drm/exynos/exynos_drm_scaler.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_drm_scaler.c > b/drivers/gpu/drm/exynos/exynos_drm_scaler.c > index ec9c1b7d31033..8989f8af716b7 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c > @@ -94,12 +94,12 @@ static inline int scaler_reset(struct scaler_context > *scaler) > scaler_write(SCALER_CFG_SOFT_RESET, SCALER_CFG); > do { > cpu_relax(); > - } while (retry > 1 && > + } while (--retry > 1 && >scaler_read(SCALER_CFG) & SCALER_CFG_SOFT_RESET); > do { > cpu_relax(); > scaler_write(1, SCALER_INT_EN); > - } while (retry > 0 && scaler_read(SCALER_INT_EN) != 1); > + } while (--retry > 0 && scaler_read(SCALER_INT_EN) != 1); > > return retry ? 0 : -EIO; If the first loop hits the retry limit the second loop won't be right and the final return value will be 0. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
[PATCH AUTOSEL 5.2 51/59] drm/exynos: fix missing decrement of retry counter
From: Colin Ian King [ Upstream commit 1bbbab097a05276e312dd2462791d32b21ceb1ee ] Currently the retry counter is not being decremented, leading to a potential infinite spin if the scalar_reads don't change state. Addresses-Coverity: ("Infinite loop") Fixes: 280e54c9f614 ("drm/exynos: scaler: Reset hardware before starting the operation") Signed-off-by: Colin Ian King Signed-off-by: Inki Dae Signed-off-by: Sasha Levin --- drivers/gpu/drm/exynos/exynos_drm_scaler.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_scaler.c b/drivers/gpu/drm/exynos/exynos_drm_scaler.c index ec9c1b7d31033..8989f8af716b7 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c +++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c @@ -94,12 +94,12 @@ static inline int scaler_reset(struct scaler_context *scaler) scaler_write(SCALER_CFG_SOFT_RESET, SCALER_CFG); do { cpu_relax(); - } while (retry > 1 && + } while (--retry > 1 && scaler_read(SCALER_CFG) & SCALER_CFG_SOFT_RESET); do { cpu_relax(); scaler_write(1, SCALER_INT_EN); - } while (retry > 0 && scaler_read(SCALER_INT_EN) != 1); + } while (--retry > 0 && scaler_read(SCALER_INT_EN) != 1); return retry ? 0 : -EIO; } -- 2.20.1 ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel