linux-kernel - Re: [Linux-fbdev-devel] radeonfb lockup in .28-rc (bisected)

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Message-ID: <87k5bhs8a7.fsf@burly.wgtn.ondioline.org>
Date:	Thu, 06 Nov 2008 19:00:48 +1300
From:	Paul Collins <paul@...ly.ondioline.org>
To:	benh@...nel.crashing.org
Cc:	James Cloos <cloos@...loos.com>,
	linux-fbdev-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	"David S. Miller" <davem@...emloft.net>,
	Krzysztof Halasa <khc@...waw.pl>
Subject: Re: [Linux-fbdev-devel] radeonfb lockup in .28-rc (bisected)

Benjamin Herrenschmidt <benh@...nel.crashing.org> writes:
> Heh, it would have been easier to do
>
> 	width = (image->width | 0x1f) + 1; 
Benjamin Herrenschmidt <benh@...nel.crashing.org> writes:
> Oh and you also need to change the src_bytes calculation 

With the slightly less embarrassing patch below applied and using the
default 8x16 font, the machine boots successfully with the expected
gibberish console display.  I can then setfont one of the large fonts
and it does not lock up.  The gibberish changes and if I do dmesg I even
get a few chunks of legible output: http://ondioline.org/~paul/corruption.png


diff --git a/drivers/video/aty/radeon_accel.c b/drivers/video/aty/radeon_accel.c
index 8718f73..6dbd24a 100644
--- a/drivers/video/aty/radeon_accel.c
+++ b/drivers/video/aty/radeon_accel.c
@@ -176,6 +176,7 @@ static void radeonfb_prim_imageblit(struct radeonfb_info *rinfo,
 {
 	unsigned int src_bytes, dwords;
 	u32 *bits;
+	int width;
 
 	radeonfb_set_creg(rinfo, DP_GUI_MASTER_CNTL, &rinfo->dp_gui_mc_cache,
 			  rinfo->dp_gui_mc_base |
@@ -208,9 +209,11 @@ static void radeonfb_prim_imageblit(struct radeonfb_info *rinfo,
 	 * work ok for me without that and the doco doesn't seem to imply
 	 * there is such a restriction.
 	 */
-	OUTREG(DST_WIDTH_HEIGHT, (image->width << 16) | image->height);
+	/* Let us pad. */
+	width = (image->width | 0x1f) + 1;
+	OUTREG(DST_WIDTH_HEIGHT, (width << 16) | image->height);
 
-	src_bytes = (((image->width * image->depth) + 7) / 8) * image->height;
+	src_bytes = (((width * image->depth) + 7) / 8) * image->height;
 	dwords = (src_bytes + 3) / 4;
 	bits = (u32*)(image->data);

-- 
Paul Collins
Wellington, New Zealand

Dag vijandelijk luchtschip de huismeester is dood
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