Bug#572311: No display output from Radeon RV610 on Alpha

[Alex Deucher]

On Fri, Mar 12, 2010 at 4:57 AM, Michael Cree <mcree at orcon.net.nz> wrote:
> On 10/03/10 08:44, Alex Deucher wrote:
>>>>>>
>>>>>> On Sun, Mar 7, 2010 at 3:47 AM, Michael Cree<mcree at orcon.net.nz>
>>>>>>  wrote:
>>>>>>>
>>>>>>> Thanks, that hint was helpful.  I have drummed up a patch (attached)
>>>>>>> that
>>>>>>> replaces some use of the UINT16LE_TO_CPU(), etc., macros with generic
>>>>>>> interfaces from the Xserver's compiler.h header file.  Now works
>>>>>>> correctly
>>>>>>> on RV610 video card on an Alpha XP1000.  Have also verified that the
>>>>>>> driver
>>>>>>> still works on an RV710 card on AMD64 architecture.
>>
>> Can you add the alignment stuff to the ATOM_BSWAP16/32 functions in
>> radeon_atombios.c?
>> e.g.,
>> return ldw_u(bswap_16(x));
>
> That's a good idea, however I think the ldw_u() must be inside the byte swap
> as the (mis)alignment issues must be dealt with at the point of loading the
> datum, whereas endianess can be fixed later.
>
> Attached is a new patch that uses the ldw_u() macros and also leaves the
> UINT16LE_TO_CPU, etc., macros in place.  Verified working on Alpha and AMD64
> architectures, but I don't have a suitable big-endian machine to test this.

Wouldn't it be cleaner to just put the ldw_u() in ATOM_BSWAP16()?

--- a/src/radeon_atombios.c
+++ b/src/radeon_atombios.c
@@ -28,6 +28,7 @@
 #endif
 #include "xf86.h"
 #include "xf86_OSproc.h"
+#include "compiler.h"

 #include "radeon.h"
 #include "radeon_reg.h"
@@ -2981,7 +2982,7 @@
atombios_get_command_table_version(atomBiosHandlePtr atomBIOS, int
index, int *m

 UINT16 ATOM_BSWAP16(UINT16 x)
 {
-    return bswap_16(x);
+    return bswap_16(ldw_u(x));
 }

 UINT32 ATOM_BSWAP32(UINT32 x)


Alex