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>
This commit is contained in:
Harvey Harrison 2008-12-13 15:21:29 -08:00 committed by Stefan Richter
parent 7d7039d365
commit c82cdea1e1

View file

@ -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();