Hello Marvin Lin,
The patch 70721089985c: "media: nuvoton: Add driver for NPCM video
capture and encoding engine" from Sep 22, 2023 (linux-next), leads to
the following Smatch static checker warning:
drivers/media/platform/nuvoton/npcm-video.c:493 npcm_video_find_rect()
warn: sleeping in atomic context
drivers/media/platform/nuvoton/npcm-video.c
488 static int npcm_video_find_rect(struct npcm_video *video,
489 struct rect_list_info *info,
490 unsigned int offset)
491 {
492 if (offset < info->tile_perline) {
--> 493 info->list = npcm_video_new_rect(video, offset, info->index);
Does a sleeping allocation.
494 if (!info->list) {
495 dev_err(video->dev, "Failed to allocate rect_list\n");
496 return -ENOMEM;
497 }
498
499 npcm_video_merge_rect(video, info);
500 }
501 return 0;
502 }
The problematic call tree is:
npcm_video_irq() <- disables preempt
-> npcm_video_hextile()
-> npcm_video_get_diff_rect()
-> npcm_video_get_rect_list()
-> npcm_video_build_table()
-> npcm_video_find_rect()
The npcm_video_irq() function holds spin_lock(&video->lock) and we can't
sleep while holding a spinlock.
regards,
dan carpenter
