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Commit 0ff8fbc6 authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter
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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: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent da28947e

drivers/firewire/ohci.c

+3 −4
Original line number Diff line number Diff line
@@ -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;