Commit 2d215d17 authored Apr 01, 2019 by Yifeng Li Committed by Greg Kroah-Hartman May 25, 2019

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 <tomli@tomli.me>
Tested-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Teddy Wang <teddy.wang@siliconmotion.com>
Cc: <stable@vger.kernel.org>  # v4.4+
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 254f5e22

drivers/video/fbdev/sm712fb.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -1493,7 +1493,11 @@ 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)