[3.13.y.z extended stable] Patch "tgafb: fix mode setting with fbset" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    tgafb: fix mode setting with fbset

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From a461e5640a38e4294d37ac80cd58924c88a31750 Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka at redhat.com>
Date: Thu, 23 Jan 2014 14:42:43 -0500
Subject: tgafb: fix mode setting with fbset

commit 624966589041deb32a2626ee2e176e8274581101 upstream.

Mode setting in the TGA driver is broken for these reasons:

- info->fix.line_length is set just once in tgafb_init_fix function. If
  we change videomode, info->fix.line_length is not recalculated - so
  the video mode is changed but the screen is corrupted because of wrong
  info->fix.line_length.

- info->fix.smem_len is set in tgafb_init_fix to the size of the default
  video mode (640x480). If we set a higher resolution,
  info->fix.smem_len is smaller than the current screen size, preventing
  the userspace program from mapping the framebuffer.

This patch fixes it:

- info->fix.line_length initialization is moved to tgafb_set_par so that
  it is recalculated with each mode change.

- info->fix.smem_len is set to a fixed value representing the real
  amount of video ram (the values are taken from xfree86 driver).

- add a check to tgafb_check_var to prevent us from setting a videomode
  that doesn't fit into videoram.

- in tgafb_register, tgafb_init_fix is moved upwards, to be called
  before fb_find_mode (because fb_find_mode already needs the videoram
  size set in tgafb_init_fix).

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
[ kamal: backport to 3.13 ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/video/tgafb.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/video/tgafb.c b/drivers/video/tgafb.c
index f28674f..6386233 100644
--- a/drivers/video/tgafb.c
+++ b/drivers/video/tgafb.c
@@ -188,6 +188,8 @@ tgafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)

 	if (var->xres_virtual != var->xres || var->yres_virtual != var->yres)
 		return -EINVAL;
+	if (var->xres * var->yres * (var->bits_per_pixel >> 3) > info->fix.smem_len)
+		return -EINVAL;
 	if (var->nonstd)
 		return -EINVAL;
 	if (1000000000 / var->pixclock > TGA_PLL_MAX_FREQ)
@@ -268,6 +270,7 @@ tgafb_set_par(struct fb_info *info)
 	par->yres = info->var.yres;
 	par->pll_freq = pll_freq = 1000000000 / info->var.pixclock;
 	par->bits_per_pixel = info->var.bits_per_pixel;
+	info->fix.line_length = par->xres * (par->bits_per_pixel >> 3);

 	tga_type = par->tga_type;

@@ -1476,6 +1479,7 @@ tgafb_init_fix(struct fb_info *info)
 	int tga_bus_tc = TGA_BUS_TC(par->dev);
 	u8 tga_type = par->tga_type;
 	const char *tga_type_name = NULL;
+	unsigned memory_size;

 	switch (tga_type) {
 	case TGA_TYPE_8PLANE:
@@ -1483,21 +1487,25 @@ tgafb_init_fix(struct fb_info *info)
 			tga_type_name = "Digital ZLXp-E1";
 		if (tga_bus_tc)
 			tga_type_name = "Digital ZLX-E1";
+		memory_size = 2097152;
 		break;
 	case TGA_TYPE_24PLANE:
 		if (tga_bus_pci)
 			tga_type_name = "Digital ZLXp-E2";
 		if (tga_bus_tc)
 			tga_type_name = "Digital ZLX-E2";
+		memory_size = 8388608;
 		break;
 	case TGA_TYPE_24PLUSZ:
 		if (tga_bus_pci)
 			tga_type_name = "Digital ZLXp-E3";
 		if (tga_bus_tc)
 			tga_type_name = "Digital ZLX-E3";
+		memory_size = 16777216;
 		break;
 	default:
 		tga_type_name = "Unknown";
+		memory_size = 16777216;
 		break;
 	}

@@ -1509,9 +1517,8 @@ tgafb_init_fix(struct fb_info *info)
 			    ? FB_VISUAL_PSEUDOCOLOR
 			    : FB_VISUAL_DIRECTCOLOR);

-	info->fix.line_length = par->xres * (par->bits_per_pixel >> 3);
 	info->fix.smem_start = (size_t) par->tga_fb_base;
-	info->fix.smem_len = info->fix.line_length * par->yres;
+	info->fix.smem_len = memory_size;
 	info->fix.mmio_start = (size_t) par->tga_regs_base;
 	info->fix.mmio_len = 512;

@@ -1635,6 +1642,9 @@ static int tgafb_register(struct device *dev)
 		modedb_tga = &modedb_tc;
 		modedbsize_tga = 1;
 	}
+
+	tgafb_init_fix(info);
+
 	ret = fb_find_mode(&info->var, info,
 			   mode_option ? mode_option : mode_option_tga,
 			   modedb_tga, modedbsize_tga, NULL,
@@ -1652,7 +1662,6 @@ static int tgafb_register(struct device *dev)
 	}

 	tgafb_set_par(info);
-	tgafb_init_fix(info);

 	if (register_framebuffer(info) < 0) {
 		printk(KERN_ERR "tgafb: Could not register framebuffer\n");
--
1.9.1