From 40e3990757fb1617ad1807e1b36ba48ed2d3a384 Mon Sep 17 00:00:00 2001 From: Yifeng Li Date: Mon, 1 Apr 2019 17:46:59 +0200 Subject: [PATCH] fbdev: sm712fb: fix boot screen glitch when sm712fb replaces VGA commit ec1587d5073f29820e358f3a383850d61601d981 upstream. When the machine is booted in VGA mode, loading sm712fb would cause a glitch of random pixels shown on the screen. To prevent it from happening, we first clear the entire framebuffer, and we also need to stop calling smtcfb_setmode() during initialization, the fbdev layer will call it for us later when it's ready. Signed-off-by: Yifeng Li Tested-by: Sudip Mukherjee Cc: Teddy Wang Cc: # v4.4+ Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/sm712fb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/sm712fb.c b/drivers/video/fbdev/sm712fb.c index a6bfa37..82fcd73 100644 --- a/drivers/video/fbdev/sm712fb.c +++ b/drivers/video/fbdev/sm712fb.c @@ -1492,7 +1492,11 @@ static int smtcfb_pci_probe(struct pci_dev *pdev, if (err) goto failed; - smtcfb_setmode(sfb); + /* + * The screen would be temporarily garbled when sm712fb takes over + * vesafb or VGA text mode. Zero the framebuffer. + */ + memset_io(sfb->lfb, 0, sfb->fb->fix.smem_len); err = register_framebuffer(info); if (err < 0) -- 2.7.4