From 0ff8fbc61727c926883eec381fbd3d32d1fab504 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Tue, 12 Apr 2011 07:54:59 +0200 Subject: [PATCH] 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 Signed-off-by: Stefan Richter --- drivers/firewire/ohci.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 435ed800d03..ce767a4882f 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -1006,13 +1006,12 @@ static void ar_context_run(struct ar_context *ctx) 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; -- 2.20.1