diff options
| author | Felipe Balbi | 2012-01-27 15:19:15 +0100 |
|---|---|---|
| committer | Sarah Sharp | 2012-03-12 17:31:24 +0100 |
| commit | 8d3709f3dd41769338cc383bec23673fd1ce34e7 (patch) | |
| tree | 414259a3c273deaf166cdc2747f1ed8b170821fd /drivers/usb | |
| parent | xHCI: BESL calculation based on USB2.0 LPM errata (diff) | |
| download | kernel-qcow2-linux-8d3709f3dd41769338cc383bec23673fd1ce34e7.tar.gz kernel-qcow2-linux-8d3709f3dd41769338cc383bec23673fd1ce34e7.tar.xz kernel-qcow2-linux-8d3709f3dd41769338cc383bec23673fd1ce34e7.zip | |
usb: host: xhci: use __ffs() instead of hardcoding shift
__ffs() can tell us which is the SEGMENT_SHIFT value
to be used. This will prevent problems when users are
too fast and don't pay attention to the need of fixing
the Shift after changing TRBS_PER_SEGMENT.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/host/xhci.h | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 0f4936956103..9a7138c29030 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1223,10 +1223,7 @@ union xhci_trb { /* Allow two commands + a link TRB, along with any reserved command TRBs */ #define MAX_RSVD_CMD_TRBS (TRBS_PER_SEGMENT - 3) #define SEGMENT_SIZE (TRBS_PER_SEGMENT*16) -/* SEGMENT_SHIFT should be log2(SEGMENT_SIZE). - * Change this if you change TRBS_PER_SEGMENT! - */ -#define SEGMENT_SHIFT 10 +#define SEGMENT_SHIFT (__ffs(SEGMENT_SIZE)) /* TRB buffer pointers can't cross 64KB boundaries */ #define TRB_MAX_BUFF_SHIFT 16 #define TRB_MAX_BUFF_SIZE (1 << TRB_MAX_BUFF_SHIFT) |