drm/exynos: fix missing decrement of retry counter

[ Upstream commit 1bbbab09 ]

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: 280e54c9 ("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

@@ -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;
 }