firewire: ohci: optimize find_branch_descriptor()
When z==2, the condition "key == 2" is superfluous because it cannot
occur without "b == 3", as a descriptor with b!=3 and key==2 would be
an OUTPUT_MORE_IMMEDIATE descriptor which cannot be used alone.
Also remove magic numbers and needless computations on the b field.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 435ed80..ce767a4 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1006,13 +1006,12 @@
static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
{
- int b, key;
+ __le16 branch;
- b = (le16_to_cpu(d->control) & DESCRIPTOR_BRANCH_ALWAYS) >> 2;
- key = (le16_to_cpu(d->control) & DESCRIPTOR_KEY_IMMEDIATE) >> 8;
+ branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
/* figure out which descriptor the branch address goes in */
- if (z == 2 && (b == 3 || key == 2))
+ if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
return d;
else
return d + z - 1;