reset_mmc_2500() is never called in atomic context.
The call chains ending up at reset_mmc_2500() are: [1] reset_mmc_2500() <- ast_dram_init_2500() <- ast_post_chip_2500() <- ast_post_gpu() <- ast_drm_thaw() [2] reset_mmc_2500() <- ast_dram_init_2500() <- 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, reset_mmc_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..12bbf64 100644 --- a/drivers/gpu/drm/ast/ast_post.c +++ b/drivers/gpu/drm/ast/ast_post.c @@ -1840,7 +1840,7 @@ static void reset_mmc_2500(struct ast_private *ast) ast_moutdwm(ast, 0x1E785044, 0x00000001); ast_moutdwm(ast, 0x1E785048, 0x00004755); ast_moutdwm(ast, 0x1E78504C, 0x00000013); - mdelay(100); + msleep(100); ast_moutdwm(ast, 0x1E785054, 0x00000077); ast_moutdwm(ast, 0x1E6E0000, 0xFC600309); }