linux-kernel - [PATCH]: Fix radeon blanking return value.

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Message-Id: <20070228.162016.74750990.davem@davemloft.net>
Date:	Wed, 28 Feb 2007 16:20:16 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	adaplas@....net
CC:	linux-kernel@...r.kernel.org
Subject: [PATCH]: 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 :-)

Signed-off-by: David S. Miller <davem@...emloft.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)
-
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