savage_init_hw() is never called in atomic context.
The call chains ending up at savage_init_hw() are:
[1] savage_init_hw() <- savagefb_probe()
[2] savage_init_hw() <- savagefb_resume()
savagefb_probe() is only set as ".probe" in struct pci_driver.
savagefb_resume) is only set as ".resume" in struct pci_driver.
These functions are not called in atomic context.
Despite never getting called from atomic context, savage_init_hw()
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range 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 <[email protected]>
---
drivers/video/fbdev/savage/savagefb_driver.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/video/fbdev/savage/savagefb_driver.c b/drivers/video/fbdev/savage/savagefb_driver.c
index c204683..c09d742 100644
--- a/drivers/video/fbdev/savage/savagefb_driver.c
+++ b/drivers/video/fbdev/savage/savagefb_driver.c
@@ -1892,11 +1892,11 @@ static int savage_init_hw(struct savagefb_par *par)
vga_out8(0x3d4, 0x66, par);
cr66 = vga_in8(0x3d5, par);
vga_out8(0x3d5, cr66 | 0x02, par);
- mdelay(10);
+ usleep_range(10000, 11000);
vga_out8(0x3d4, 0x66, par);
vga_out8(0x3d5, cr66 & ~0x02, par); /* clear reset flag */
- mdelay(10);
+ usleep_range(10000, 11000);
/*
@@ -1906,11 +1906,11 @@ static int savage_init_hw(struct savagefb_par *par)
vga_out8(0x3d4, 0x3f, par);
cr3f = vga_in8(0x3d5, par);
vga_out8(0x3d5, cr3f | 0x08, par);
- mdelay(10);
+ usleep_range(10000, 11000);
vga_out8(0x3d4, 0x3f, par);
vga_out8(0x3d5, cr3f & ~0x08, par); /* clear reset flags */
- mdelay(10);
+ usleep_range(10000, 11000);
/* Savage ramdac speeds */
par->numClocks = 4;
--
1.9.1
On Tuesday, April 10, 2018 09:05:59 AM Jia-Ju Bai wrote:
> savage_init_hw() is never called in atomic context.
>
> The call chains ending up at savage_init_hw() are:
> [1] savage_init_hw() <- savagefb_probe()
> [2] savage_init_hw() <- savagefb_resume()
>
> savagefb_probe() is only set as ".probe" in struct pci_driver.
> savagefb_resume) is only set as ".resume" in struct pci_driver.
> These functions are not called in atomic context.
>
> Despite never getting called from atomic context, savage_init_hw()
> calls mdelay() to busily wait.
> This is not necessary and can be replaced with usleep_range 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 <[email protected]>
Patch queued for 4.18, thanks.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics