drm/radeon/kms/atom: use get_unaligned_le32() for ctx->ps

Noticed on a DEC Alpha.

Start up into console mode caused 15 unaligned accesses, and starting X
caused another 48.

Signed-off-by: Matt Turner <mattst88@gmail.com>
CC: Jerome Glisse <jglisse@redhat.com>
CC: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index e3b44562d2654f7ab2c29da917d50a864db736ef..2a3df5599ab48b0056fc2a4ad4b2d37bac29b4a1 100644 (file)
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -24,6 +24,7 @@
 
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <asm/unaligned.h>
 
 #define ATOM_DEBUG
 
@@ -212,7 +213,9 @@ static uint32_t atom_get_src_int(atom_exec_context *ctx, uint8_t attr,
        case ATOM_ARG_PS:
                idx = U8(*ptr);
                (*ptr)++;
-               val = le32_to_cpu(ctx->ps[idx]);
+               /* get_unaligned_le32 avoids unaligned accesses from atombios
+                * tables, noticed on a DEC Alpha. */
+               val = get_unaligned_le32((u32 *)&ctx->ps[idx]);
                if (print)
                        DEBUG("PS[0x%02X,0x%04X]", idx, val);
                break;