USB: ehci saves some memory in ISO transfer descriptors

In the EHCI driver, itd->usecs[8] is used in periodic_usecs(), indexed by
uframe.  For an ITD's unused uframes it is 0, else it contains the same
value as itd->stream->usecs.  To check if an ITD's uframe is used, we can
instead test itd->hw_transaction[uframe]:  if used, it will be nonzero no
matter what endianess is used.

This patch replaces those two uses, eliminates itd->usecs[], and saves
eight bytes from each ITD.

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Karsten Wiese 2007-12-30 21:55:05 -08:00 committed by Greg Kroah-Hartman
parent 91bc4d31e8
commit 3b6fcfd066
2 changed files with 2 additions and 3 deletions

View file

@ -119,7 +119,8 @@ periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe)
q = &q->fstn->fstn_next;
break;
case Q_TYPE_ITD:
usecs += q->itd->usecs [uframe];
if (q->itd->hw_transaction[uframe])
usecs += q->itd->stream->usecs;
hw_p = &q->itd->hw_next;
q = &q->itd->itd_next;
break;
@ -1536,7 +1537,6 @@ itd_link_urb (
uframe = next_uframe & 0x07;
frame = next_uframe >> 3;
itd->usecs [uframe] = stream->usecs;
itd_patch(ehci, itd, iso_sched, packet, uframe);
next_uframe += stream->interval;

View file

@ -602,7 +602,6 @@ struct ehci_itd {
unsigned frame; /* where scheduled */
unsigned pg;
unsigned index[8]; /* in urb->iso_frame_desc */
u8 usecs[8];
} __attribute__ ((aligned (32)));
/*-------------------------------------------------------------------------*/