Messages in this thread Patch in this message | | | From | Jia-Ju Bai <> | Subject | [PATCH 2/2] gpu: drm: ast: Replace mdelay with msleep in ast_post_chip_2500 | Date | Wed, 11 Apr 2018 16:30:16 +0800 |
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ast_post_chip_2500() is never called in atomic context.
The call chains ending up at reset_mmc_2500() are: [1] ast_post_chip_2500() <- ast_post_gpu() <- ast_drm_thaw() [2] ast_post_chip_2500() <- ast_post_gpu() <- ast_driver_load()
ast_drm_thaw() calls console_lock() which can sleep. ast_driver_load() is set as ".load" in struct drm_driver. These functions are not called in atomic context.
Despite never getting called from atomic context, ast_post_chip_2500() calls mdelay() to busily wait. This is not necessary and can be replaced with msleep() to avoid busy waiting.
This is found by a static analysis tool named DCNS written by myself. And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/gpu/drm/ast/ast_post.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ast/ast_post.c b/drivers/gpu/drm/ast/ast_post.c index f7d4213..67c5e50 100644 --- a/drivers/gpu/drm/ast/ast_post.c +++ b/drivers/gpu/drm/ast/ast_post.c @@ -2063,7 +2063,7 @@ void ast_post_chip_2500(struct drm_device *dev) temp = ast_mindwm(ast, 0x1e6e2070); if (temp & 0x00800000) { ast_moutdwm(ast, 0x1e6e207c, 0x00800000); - mdelay(100); + msleep(100); ast_moutdwm(ast, 0x1e6e2070, 0x00800000); } -- 1.9.1
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