Re: controlfb and X (fixed)

Re: controlfb and X (fixed)

[Michel Lanners]

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Hi all,

Some time ago, there were reports of crashes with controlfb and 2.4
kernels, while starting XF4.0.

I've taken a look, and it seems that indeed the mmap code recently added
to controlfb is to blame.

Below is the patch that fixes the hanging box while starting X for me.
It seems while implementing mmap() for 2.4 kernels in controlfb, I
forgot to copy 2 lines :-((

Ben and Paul, could you apply this patch to all your 2.4 / 2.5 trees? It
also fixes the 7_spaces_instead_of_tab problem in the mmap() code ;-)

Cheers, happy hacking, and sorry for this bug :-)

Michel

-------------------------------------------------------------------------
Michel Lanners                 |  " Read Philosophy.  Study Art.
23, Rue Paul Henkes            |    Ask Questions.  Make Mistakes.
L-1710 Luxembourg              |
email   mlan@cpu.lu            |
http://www.cpu.lu/~mlan        |                     Learn Always. "

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--- /mnt/r4/usr/src/linux-2.4.paul/drivers/video/controlfb.c	Thu Oct 19 03:36:07 2000
+++ linux-2.4.0-test10/drivers/video/controlfb.c	Sat Nov 18 19:23:10 2000
@@ -338,38 +343,41 @@
 static int control_mmap(struct fb_info *info, struct file *file,
                        struct vm_area_struct *vma)
 {
-       struct fb_ops *fb = info->fbops;
-       struct fb_fix_screeninfo fix;
-       struct fb_var_screeninfo var;
-       unsigned long off, start;
-       u32 len;
-
-       fb->fb_get_fix(&fix, PROC_CONSOLE(info), info);
-       off = vma->vm_pgoff << PAGE_SHIFT;
-
-       /* frame buffer memory */
-       start = fix.smem_start;
-       len = PAGE_ALIGN((start & ~PAGE_MASK)+fix.smem_len);
-       if (off >= len) {
-               /* memory mapped io */
-               off -= len;
-               fb->fb_get_var(&var, PROC_CONSOLE(info), info);
-               if (var.accel_flags)
-                       return -EINVAL;
-               start = fix.mmio_start;
-               len = PAGE_ALIGN((start & ~PAGE_MASK)+fix.mmio_len);
-               pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE|_PAGE_GUARDED;
-       } else {
-               /* framebuffer */
-               pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
-       }
-       start &= PAGE_MASK;
-       vma->vm_pgoff = off >> PAGE_SHIFT;
-       if (io_remap_page_range(vma->vm_start, off,
-           vma->vm_end - vma->vm_start, vma->vm_page_prot))
-               return -EAGAIN;
+	struct fb_ops *fb = info->fbops;
+	struct fb_fix_screeninfo fix;
+	struct fb_var_screeninfo var;
+	unsigned long off, start;
+	u32 len;

-       return 0;
+	fb->fb_get_fix(&fix, PROC_CONSOLE(info), info);
+	off = vma->vm_pgoff << PAGE_SHIFT;
+
+	/* frame buffer memory */
+	start = fix.smem_start;
+	len = PAGE_ALIGN((start & ~PAGE_MASK)+fix.smem_len);
+	if (off >= len) {
+		/* memory mapped io */
+		off -= len;
+		fb->fb_get_var(&var, PROC_CONSOLE(info), info);
+		if (var.accel_flags)
+			return -EINVAL;
+		start = fix.mmio_start;
+		len = PAGE_ALIGN((start & ~PAGE_MASK)+fix.mmio_len);
+		pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE|_PAGE_GUARDED;
+	} else {
+		/* framebuffer */
+		pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
+	}
+	start &= PAGE_MASK;
+	if ((vma->vm_end - vma->vm_start + off) > len)
+		return -EINVAL;
+	off += start;
+	vma->vm_pgoff = off >> PAGE_SHIFT;
+	if (io_remap_page_range(vma->vm_start, off,
+	    vma->vm_end - vma->vm_start, vma->vm_page_prot))
+		return -EAGAIN;
+
+	return 0;
 }

Re: controlfb and X (fixed)

[Robert E Brose II]

User Michel Lanners says:
>
> > Which 2.4.0 kernel source are YOU using?
>
> I'm running BenH's 2.5 kernel, that's the only one I was able to boot on
> my 7600. Paulus' 2.4 kernels lock my machine 90% of the time at boot. I
> haven't found what's wrong with them, though...
>
> BenH's kernel is at:
>
> rsync -arvz penguinppc.org::linux-benh-devel .
>
> Happy compiling ;-)

FINALLY got the 2.4.0-test10 benh kernel going.
I had to turn off a bunch of stuff to get it to run (i.e. to avoid
the black screen of death on boot) and I'm not sure the
PPP async driver works yet, had to compile it as a module.

The controlfb driver now senses the 4m video memory properly
on the 7500.

XFree4.01 runs (though the keyboard is messed up. I have to investigate
the new input layer)

The stock XFree86 (XFree86-3.3.6-11.2) also works in 24/32 bits now!!!
HOORAY!! Hopefully the changes will eventually make it to the stock
trees.

Thanks Michel!

Bob
--
Robert E. Brose II    N0QBJ
http://www.jriver.com/~bob/
bob@kunk.jriver.com


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