tree 746b934bda84867cfef0c87682d4ee0c89929604
parent c21599a36165dbc78b380846b254017a548b9de5
author Sarah Sharp <sarah.a.sharp@linux.intel.com> 1280466797 -0700
committer Greg Kroah-Hartman <gregkh@suse.de> 1281476145 -0700

USB: xhci: Don't flush doorbell writes.

To tell the host controller that there are transfers on the endpoint
rings, we need to ring the endpoint doorbell.  This is a PCI MMIO write,
which can be delayed until another register read is queued.

The previous code would flush the doorbell write by reading the doorbell
register after the write.  This may take time, and it's not necessary to
force the host controller to know about the transfers right away.  Don't
flush the doorbell register writes.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>