linux-kernel - [PATCH AUTOSEL for 4.4 092/167] vfb: fix video mode and line

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Date:   Mon, 19 Mar 2018 16:07:17 +0000
From:   Sasha Levin <Alexander.Levin@...rosoft.com>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
CC:     "Pieter \\\"PoroCYon\\\" Sluys" <pcy@...ional.shitposting.agency>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Sasha Levin <Alexander.Levin@...rosoft.com>
Subject: [PATCH AUTOSEL for 4.4 092/167] vfb: fix video mode and line_length
 being set when loaded

From: "Pieter \\\"PoroCYon\\\" Sluys" <pcy@...ional.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@...ional.shitposting.agency>
Reviewed-by: Geert Uytterhoeven <geert@...ux-m68k.org>
[b.zolnierkie: minor fixups]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.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 b9c2f81fb6b9..556c39997aab 100644
--- a/drivers/video/fbdev/vfb.c
+++ b/drivers/video/fbdev/vfb.c
@@ -291,8 +291,23 @@ 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;
 }
 
@@ -525,6 +540,8 @@ 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