2018-08-04 00:07:02

by Jia-Ju Bai

[permalink] [raw]
Subject: [PATCH] gpu: drm: radeon: rs600: Replace mdelay() with msleep() and usleep_range() in rs600_asic_reset()

rs600_asic_reset() is never called in atomic context.
They call mdelay() to busily wait, which is not necessary.
mdelay() can be replaced with msleep() and usleep_range().

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/gpu/drm/radeon/rs600.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index f16af119c688..1a97f5fd719b 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -472,30 +472,30 @@ int rs600_asic_reset(struct radeon_device *rdev, bool hard)
pci_save_state(rdev->pdev);
/* disable bus mastering */
pci_clear_master(rdev->pdev);
- mdelay(1);
+ usleep_range(1000, 2000);
/* reset GA+VAP */
WREG32(R_0000F0_RBBM_SOFT_RESET, S_0000F0_SOFT_RESET_VAP(1) |
S_0000F0_SOFT_RESET_GA(1));
RREG32(R_0000F0_RBBM_SOFT_RESET);
- mdelay(500);
+ msleep(500);
WREG32(R_0000F0_RBBM_SOFT_RESET, 0);
- mdelay(1);
+ usleep_range(1000, 2000);
status = RREG32(R_000E40_RBBM_STATUS);
dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
/* reset CP */
WREG32(R_0000F0_RBBM_SOFT_RESET, S_0000F0_SOFT_RESET_CP(1));
RREG32(R_0000F0_RBBM_SOFT_RESET);
- mdelay(500);
+ msleep(500);
WREG32(R_0000F0_RBBM_SOFT_RESET, 0);
- mdelay(1);
+ usleep_range(1000, 2000);
status = RREG32(R_000E40_RBBM_STATUS);
dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
/* reset MC */
WREG32(R_0000F0_RBBM_SOFT_RESET, S_0000F0_SOFT_RESET_MC(1));
RREG32(R_0000F0_RBBM_SOFT_RESET);
- mdelay(500);
+ msleep(500);
WREG32(R_0000F0_RBBM_SOFT_RESET, 0);
- mdelay(1);
+ usleep_range(1000, 2000);
status = RREG32(R_000E40_RBBM_STATUS);
dev_info(rdev->dev, "(%s:%d) RBBM_STATUS=0x%08X\n", __func__, __LINE__, status);
/* restore PCI & busmastering */
--
2.17.0