[PATCH AUTOSEL for 4.14 37/97] vfb: fix video mode and line_length being set when loaded

Sasha Levin
2018-03-19T15:55:50Z

From: "Pieter \\\"PoroCYon\\\" Sluys" <pcy@national.shitposting.agency>

[ Upstream commit 7b9faf5df0ac495a1a3d7cdb64921c179f9008ac ]

Currently, when loading the vfb module, the newly created fbdev
has a line_length of 0, and its video mode would be PSEUDOCOLOR
regardless of color depth. (The former could be worked around by
calling the FBIOPUT_VSCREENINFO ioctl with having the FBACTIVIATE_FORCE
flag set.) This patch automatically sets the line_length correctly,
and the video mode is derived from the bit depth now as well.

Thanks to Geert Uytterhoeven for confirming the bug and helping me with
the patch.

Output of `fbset -i' before the patch:
mode "1366x768-60"
# D: 72.432 MHz, H: 47.403 kHz, V: 60.004 Hz
geometry 1366 768 1366 768 32
timings 13806 120 10 14 3 32 5
rgba 8/0,8/8,8/16,8/24
endmode

Frame buffer device information:
Name : Virtual FB
Address : 0xffffaa1405d85000
Size : 4196352
Type : PACKED PIXELS
Visual : PSEUDOCOLOR
XPanStep : 1
YPanStep : 1
YWrapStep : 1
LineLength : 0 <-- note this
Accelerator : No

After:
mode "1366x768-60"
# D: 72.432 MHz, H: 47.403 kHz, V: 60.004 Hz
geometry 1366 768 1366 768 32
timings 13806 120 10 14 3 32 5
rgba 8/0,8/8,8/16,8/24
endmode

Frame buffer device information:
Name : Virtual FB
Address : 0xffffaa1405d85000
Size : 4196352
Type : PACKED PIXELS
Visual : TRUECOLOR
XPanStep : 1
YPanStep : 1
YWrapStep : 1
LineLength : 5464
Accelerator : No

Signed-off-by: "Pieter \"PoroCYon\" Sluys" <pcy@national.shitposting.agency>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
[b.zolnierkie: minor fixups]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/video/fbdev/vfb.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)

diff --git a/drivers/video/fbdev/vfb.c b/drivers/video/fbdev/vfb.c
index da653a080394..54127905bfe7 100644
--- a/drivers/video/fbdev/vfb.c
+++ b/drivers/video/fbdev/vfb.c
@@ -239,8 +239,23 @@ static int vfb_check_var(struct fb_var_screeninfo *var,
*/
static int vfb_set_par(struct fb_info *info)
{
+ switch (info->var.bits_per_pixel) {
+ case 1:
+ info->fix.visual = FB_VISUAL_MONO01;
+ break;
+ case 8:
+ info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
+ break;
+ case 16:
+ case 24:
+ case 32:
+ info->fix.visual = FB_VISUAL_TRUECOLOR;
+ break;
+ }
+
info->fix.line_length = get_line_length(info->var.xres_virtual,
info->var.bits_per_pixel);
+
return 0;
}

@@ -450,6 +465,8 @@ static int vfb_probe(struct platform_device *dev)
goto err2;
platform_set_drvdata(dev, info);

+ vfb_set_par(info);
+
fb_info(info, "Virtual frame buffer device, using %ldK of video memory\n",
videomemorysize >> 10);
return 0;
--
2.14.1