Messages in this thread Patch in this message | | | Date | Sat, 17 Aug 2019 21:47:54 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.2 51/59] drm/exynos: fix missing decrement of retry counter |
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On Wed, Aug 07, 2019 at 08:49:52AM +0000, David Laight wrote: >From: Sasha Levin >> Sent: 06 August 2019 22:33 >> >> From: Colin Ian King <colin.king@canonical.com> >> >> [ 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 <colin.king@canonical.com> >> Signed-off-by: Inki Dae <inki.dae@samsung.com> >> Signed-off-by: Sasha Levin <sashal@kernel.org> >> --- >> 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
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