[PATCH 4.19 50/85] drm/exynos: fix missing decrement of retry counter

Greg Kroah-Hartman
2019-08-22T17:31:45Z

[ 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 0ddb6eec7b113..df228436a03d9 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_scaler.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_scaler.c
@@ -108,12 +108,12 @@ 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