ieee1934: dv1394: interrupt enabling/disabling broken on big-endian

After annotating the frame structs, this was left:
drivers/ieee1394/dv1394.c:2113:23: warning: invalid assignment: |=
drivers/ieee1394/dv1394.c:2113:23:    left side has type restricted __le32
drivers/ieee1394/dv1394.c:2113:23:    right side has type int
drivers/ieee1394/dv1394.c:2121:24: warning: invalid assignment: &=
drivers/ieee1394/dv1394.c:2121:24:    left side has type restricted __le32
drivers/ieee1394/dv1394.c:2121:24:    right side has type int
drivers/ieee1394/dv1394.c:2123:24: warning: invalid assignment: |=
drivers/ieee1394/dv1394.c:2123:24:    left side has type restricted __le32
drivers/ieee1394/dv1394.c:2123:24:    right side has type int

Which looks like a real bug on a big-endian arch as it would set/clear
the wrong bit.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Bill Fink writes:

I finally got a chance to test the patch on my kernel, and live DV
viewing using xine still worked fine.  Although I admit to being
mystified how it works both before and after the patch, since the
cpu_to_le32() calls that were added should result in byte swapping on
PPC that wasn't being done before.  I guess that either the code paths
involved aren't actually being triggered by my xine DV viewing, or
there's some fortuitous palindromic setting of bits.

Tested-by: Bill Fink <billfink@mindspring.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c
index f258e618389ce50b6119d08812ba0f870802f9ec..a329e6bd5d2d47b26f147f8a8169234b95e94600 100644 (file)
--- a/drivers/ieee1394/dv1394.c
+++ b/drivers/ieee1394/dv1394.c
@@ -2110,17 +2110,17 @@ static void ir_tasklet_func(unsigned long data)
                        f = video->frames[next_i / MAX_PACKETS];
                        next = &(f->descriptor_pool[next_i % MAX_PACKETS]);
                        next_dma = ((unsigned long) block - (unsigned long) f->descriptor_pool) + f->descriptor_pool_dma;
-                       next->u.in.il.q[0] |= 3 << 20; /* enable interrupt */
-                       next->u.in.il.q[2] = 0; /* disable branch */
+                       next->u.in.il.q[0] |= cpu_to_le32(3 << 20); /* enable interrupt */
+                       next->u.in.il.q[2] = cpu_to_le32(0); /* disable branch */
 
                        /* link previous to next */
                        prev_i = (next_i == 0) ? (MAX_PACKETS * video->n_frames - 1) : (next_i - 1);
                        f = video->frames[prev_i / MAX_PACKETS];
                        prev = &(f->descriptor_pool[prev_i % MAX_PACKETS]);
                        if (prev_i % (MAX_PACKETS/2)) {
-                               prev->u.in.il.q[0] &= ~(3 << 20); /* no interrupt */
+                               prev->u.in.il.q[0] &= ~cpu_to_le32(3 << 20); /* no interrupt */
                        } else {
-                               prev->u.in.il.q[0] |= 3 << 20; /* enable interrupt */
+                               prev->u.in.il.q[0] |= cpu_to_le32(3 << 20); /* enable interrupt */
                        }
                        prev->u.in.il.q[2] = cpu_to_le32(next_dma | 1); /* set Z=1 */
                        wmb();