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bochs-drm: disable video before changing video mode

PATCH In review Chris Ruffin 4 participants 4 messages Mar 18, 2015 – Mar 31, 2015

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Chris Ruffin

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#0 lore raw

PATCH 1/1 bochs-drm: disable video before changing video mode

qemu and simics simulators both seem to expect that video should be disabled before changing the video mode.

references:
http://git.qemu.org/?p=qemu.git;a=blob;f=hw/display/vga.c;h=c0f7b343bbab586c8593d29c7a765f1e6ca3662c;hb=HEAD#l727
http://wiki.osdev.org/Bochs_VBE_Extensions#Setting_display_resolution_and_bit_depth

Signed-off-by Chris Ruffin <[email protected]>
---
 drivers/gpu/drm/bochs/bochs_hw.c |    1 +
 1 file changed, 1 insertion(+)
drivers/gpu/drm/bochs/bochs_hw.c +1 -0
index 4603897..a39b034 100644
@@ -164,6 +164,7 @@ void bochs_hw_setmode(struct bochs_device *bochs,
 
 	bochs_vga_writeb(bochs, 0x3c0, 0x20); /* unblank */
 
+	bochs_dispi_write(bochs, VBE_DISPI_INDEX_ENABLE,      0);
 	bochs_dispi_write(bochs, VBE_DISPI_INDEX_BPP,         bochs->bpp);
 	bochs_dispi_write(bochs, VBE_DISPI_INDEX_XRES,        bochs->xres);
 	bochs_dispi_write(bochs, VBE_DISPI_INDEX_YRES,        bochs->yres);
Signature · 1 line
1.7.10.4
Reviewed-by on v1 1/1
#1 lore raw
Quoted 2 lines · Chris Ruffin

qemu and simics simulators both seem to expect that video should be disabled before changing the video mode.

Not required for qemu. qemu allows updating the modesetting registers (xres + friends) while vbe is enabled.

Turning it off, then back on after updating the registers doesn't hurt though. So if this change gets things going on simics it's fine with me.

Reviewed-by Gerd Hoffmann <[email protected]>

cheers,
Gerd

#2 lore raw
Quoted 4 lines · Gerd Hoffmann
Quoted 2 lines · Chris Ruffin

qemu and simics simulators both seem to expect that video should be disabled before changing the video mode.

Quoted 8 lines

Not required for qemu. qemu allows updating the modesetting registers (xres + friends) while vbe is enabled.

Turning it off, then back on after updating the registers doesn't hurt though. So if this change gets things going on simics it's fine with me.

Reviewed-by Gerd Hoffmann <[email protected]>

Hi Gerd, Dave,
I can't find the patch in linux-next,
will it be included in 4.1?

#3 lore raw

----- Original Message -----

Quoted 21 lines

From: "Alexander Beregalov" <[email protected]>
To: "Gerd Hoffmann" <[email protected]>
Cc: "Chris Ruffin" <[email protected]>, "Linux Kernel Mailing List" <[email protected]>, "Dave Airlie" <[email protected]>, [email protected], "Alexander Beregalov" <[email protected]>, "alexey buyanov" <[email protected]>
Sent: Wednesday, 1 April, 2015 2:13:33 AM
Subject: Re: [PATCH] bochs-drm: disable video before changing video mode

Quoted 12 lines · Gerd Hoffmann
Quoted 3 lines · Chris Ruffin

qemu and simics simulators both seem to expect that video should be disabled
before changing the video mode.

Not required for qemu. qemu allows updating the modesetting registers (xres + friends) while vbe is enabled.

Turning it off, then back on after updating the registers doesn't hurt though. So if this change gets things going on simics it's fine with me.

Quoted 5 lines
Quoted 1 line
Reviewed-by Gerd Hoffmann <[email protected]>

Hi Gerd, Dave,
I can't find the patch in linux-next,
will it be included in 4.1?

Just added it now.

Thanks,
Dave.

Quoted 1 line