Thread (11 messages) 11 messages, 2 authors, 2013-12-04

Re: [PATCH v2] offb: make the screen properties endian safe

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2013-11-20 22:50:15

On Thu, 2013-10-31 at 10:36 +0100, Cédric Le Goater wrote:
The "screen" properties : depth, width, height, linebytes need
to be converted to the host endian order when read from the device
tree.

Signed-off-by: Cédric Le Goater <redacted>
---
Did you actually test that ? IE, using emulated VGA in qemu for
example ?

I'm asking because there are a few interesting nits here...

 - fbdev *generally* assume native endian framebuffer, but of course
under qemu today, the adapter will use a big endian frame buffer
aperture. You can compile in support for foreign endian but I don't know
how that actually works.

 - The setcolreg fix ... the "value" is used 2 lines above your endian
swap, is that correct ?

Cheers
Ben.

quoted hunk ↗ jump to hunk
Changes in v2:

 - replaced be32_to_cpu() by be32_to_cpup() 
 - fixed setcolreg ops 

 drivers/video/offb.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/video/offb.c b/drivers/video/offb.c
index 0c4f343..68e8415 100644
--- a/drivers/video/offb.c
+++ b/drivers/video/offb.c
@@ -120,7 +120,7 @@ static int offb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 			mask <<= info->var.transp.offset;
 			value |= mask;
 		}
-		pal[regno] = value;
+		pal[regno] = cpu_to_be32(value);
 		return 0;
 	}
 
@@ -536,7 +536,7 @@ static void __init offb_init_nodriver(struct device_node *dp, int no_real_node)
 	unsigned int flags, rsize, addr_prop = 0;
 	unsigned long max_size = 0;
 	u64 rstart, address = OF_BAD_ADDR;
-	const u32 *pp, *addrp, *up;
+	const __be32 *pp, *addrp, *up;
 	u64 asize;
 	int foreign_endian = 0;
 
@@ -552,25 +552,25 @@ static void __init offb_init_nodriver(struct device_node *dp, int no_real_node)
 	if (pp == NULL)
 		pp = of_get_property(dp, "depth", &len);
 	if (pp && len == sizeof(u32))
-		depth = *pp;
+		depth = be32_to_cpup(pp);
 
 	pp = of_get_property(dp, "linux,bootx-width", &len);
 	if (pp == NULL)
 		pp = of_get_property(dp, "width", &len);
 	if (pp && len == sizeof(u32))
-		width = *pp;
+		width = be32_to_cpup(pp);
 
 	pp = of_get_property(dp, "linux,bootx-height", &len);
 	if (pp == NULL)
 		pp = of_get_property(dp, "height", &len);
 	if (pp && len == sizeof(u32))
-		height = *pp;
+		height = be32_to_cpup(pp);
 
 	pp = of_get_property(dp, "linux,bootx-linebytes", &len);
 	if (pp == NULL)
 		pp = of_get_property(dp, "linebytes", &len);
 	if (pp && len == sizeof(u32) && (*pp != 0xffffffffu))
-		pitch = *pp;
+		pitch = be32_to_cpup(pp);
 	else
 		pitch = width * ((depth + 7) / 8);
 
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help