Commit 12f3ac2f authored Apr 24, 2018 by Jia-Ju Bai Committed by Bartlomiej Zolnierkiewicz Apr 24, 2018

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>

parent 8cad95f5

drivers/video/fbdev/savage/savagefb_driver.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -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;

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