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: Fix radeon blanking return value.

PATCH In review David Miller 2 participants 2 messages Mar 1, 2007 Framebuffer layer

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PATCH 1/1 : Fix radeon blanking return value.

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 :-)

drivers/video/aty/radeon_base.c +1 -2
index c32b714..af7eb07 100644
@@ -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)
Acked-by on v1 1/1
#1 lore raw
Quoted 27 lines · 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:

Quoted 8 lines
		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.

Quoted 2 lines

Tony