[PATCH v2] offb: make the screen properties endian safe
Cedric Le Goater
clg at fr.ibm.com
Fri Nov 22 02:45:13 EST 2013
Hi,
On 11/20/2013 11:50 PM, Benjamin Herrenschmidt wrote:
> 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 <clg at fr.ibm.com>
>> ---
>
> Did you actually test that ? IE, using emulated VGA in qemu for
> example ?
Yes, that's how I did. I ran LE and BE guests with "qemu -vga std" and
different depths.
> 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.
OK. I will see how I can extend the tests. But, are you suggesting I should
be using the foreign endian framework for the frame buffer ?
> - The setcolreg fix ... the "value" is used 2 lines above your endian
> swap, is that correct ?
The variables used to calculate "value" are in host endian order. It should
be fine.
Thanks,
C.
> Cheers
> Ben.
>
>
>> 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);
>>
>
>
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