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video: fbdev: savage: Replace mdelay with usleep_range in savage_init_hw 

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>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
This commit is contained in:
Jia-Ju Bai 2018-04-24 18:11:21 +02:00 committed by Bartlomiej Zolnierkiewicz
parent 8cad95f56f
commit 12f3ac2fb1
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/video/fbdev/savage/savagefb_driver.c
View File

@ -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;