[PATCH]: Fix radeon blanking return value.

[PATCH]: Fix radeon blanking return value.

[David Miller]

If you'll recall, over a year ago, I pointed out that the current
Radeon driver erroneously returns -EINVAL for valid blanking codes,
here is a link to that thread:

	http://lkml.org/lkml/2006/1/28/6

No other driver does this, and it confuses the X server into thinking
that the device does not support blanking properly.

As a result I have to switch to a console VC and back to the X server
to unblank the screen, which is rediculious.

I've had to do this for more than 3 years and I'm really tired of this
problem still being around :-)

I looked again and there is simply no reason for the Radeon driver to
return -EINVAL for FB_BLANK_NORMAL.  It claims it wants to do this in
order to convince fbcon to blank in software, right here:

			if (fb_blank(info, blank))
				fbcon_generic_blank(vc, info, blank);

to software blank the screen.  But it only causes that to happen
in the FB_BLANK_NORMAL case.

That makes no sense because the Radeon code does this:

		val |= CRTC_DISPLAY_DIS;

in the FB_BLANK_NORMAL case so should be blanking the hardware, and
there is therefore no reason to SW blank by returning -EINVAL.

Therefore I propose we finally apply the following patch.  No other
fbdev driver does this madness, and as I've shown above there is no
justification for the behavior at all :-)

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/video/aty/radeon_base.c b/drivers/video/aty/radeon_base.c
index c32b714..af7eb07 100644
--- a/drivers/video/aty/radeon_base.c
+++ b/drivers/video/aty/radeon_base.c
@@ -1032,8 +1032,7 @@ int radeon_screen_blank(struct radeonfb_info *rinfo, int blank, int mode_switch)
 		break;
 	}
 
-	/* let fbcon do a soft blank for us */
-	return (blank == FB_BLANK_NORMAL) ? -EINVAL : 0;
+	return 0;
 }
 
 static int radeonfb_blank (int blank, struct fb_info *info)

Re: [PATCH]: Fix radeon blanking return value.

[Antonino A. Daplas]

On Wed, 2007-02-28 at 16:20 -0800, David Miller wrote:
> If you'll recall, over a year ago, I pointed out that the current
> Radeon driver erroneously returns -EINVAL for valid blanking codes,
> here is a link to that thread:
> 
> 	http://lkml.org/lkml/2006/1/28/6
> 
> No other driver does this, and it confuses the X server into thinking
> that the device does not support blanking properly.
> 
> As a result I have to switch to a console VC and back to the X server
> to unblank the screen, which is rediculious.
> 
> I've had to do this for more than 3 years and I'm really tired of this
> problem still being around :-)
> 
> I looked again and there is simply no reason for the Radeon driver to
> return -EINVAL for FB_BLANK_NORMAL.  It claims it wants to do this in
> order to convince fbcon to blank in software, right here:
> 
> 			if (fb_blank(info, blank))
> 				fbcon_generic_blank(vc, info, blank);
> 
> to software blank the screen.  But it only causes that to happen
> in the FB_BLANK_NORMAL case.
> 
> That makes no sense because the Radeon code does this:
> 
> 		val |= CRTC_DISPLAY_DIS;
> 
> in the FB_BLANK_NORMAL case so should be blanking the hardware, and
> there is therefore no reason to SW blank by returning -EINVAL.
> 
> Therefore I propose we finally apply the following patch.  No other
> fbdev driver does this madness, and as I've shown above there is no
> justification for the behavior at all :-)

This was before radeonfb did not fully differentiate each blanking
levels.  Currently, it is fixed, so I agree with this patch.

> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Antonino Daplas <adaplas@gmail.com>

Tony