Patch "vfb: fix video mode and line_length being set when loaded" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

vfb: fix video mode and line_length being set when loaded

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
vfb-fix-video-mode-and-line_length-being-set-when-loaded.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Pieter \\\"PoroCYon\\\" Sluys" <[email protected]>
Date: Thu, 4 Jan 2018 16:53:50 +0100
Subject: vfb: fix video mode and line_length being set when loaded

From: "Pieter \\\"PoroCYon\\\" Sluys" <[email protected]>

[ 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

---
 drivers/video/fbdev/vfb.c |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

@@ -239,8 +239,23 @@ static int vfb_check_var(struct fb_var_s
  */
 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_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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/vfb-fix-video-mode-and-line_length-being-set-when-loaded.patch