From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Date: Tue, 10 Apr 2018 01:05:59 +0000 Subject: [PATCH] video: fbdev: savage: Replace mdelay with usleep_range in savage_init_hw Message-Id: <1523322359-27598-1-git-send-email-baijiaju1990@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: adaplas@gmail.com, b.zolnierkie@samsung.com Cc: linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai 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 --- 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