| Message ID | 1523322359-27598-1-git-send-email-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <baijiaju1990@gmail.com> Patch queued for 4.18, thanks. Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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 <baijiaju1990@gmail.com> --- drivers/video/fbdev/savage/savagefb_driver.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)