diff options
| author | Ming Lei <ming.lei@canonical.com> | 2011-08-31 00:03:13 +0800 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-10-10 22:39:25 -0400 |
| commit | 5d9d49c51678f5e4c37ce661b4573d73fb391040 (patch) | |
| tree | aef36fb40b217e527db7b4a296b0be528fdc11cc /drivers/tty | |
| parent | 65112dccf8a113737684366349d7f9ec373ddc47 (diff) | |
usb: ehci: make HC see up-to-date qh/qtd descriptor ASAP
This patch introduces the helper of ehci_sync_mem to flush
qtd/qh into memory immediately on some ARM, so that HC can
see the up-to-date qtd/qh descriptor asap.
This patch fixs one performance bug on ARM Cortex A9 dual core
platform, which has been reported on quite a few ARM machines
(OMAP4, Tegra 2, snowball...), see details from link of
https://bugs.launchpad.net/bugs/709245.
The patch has been tested ok on OMAP4 panda A1 board, and the
performance of 'dd' over usb mass storage can be increased from
4~5MB/sec to 14~16MB/sec after applying this patch.
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Diffstat (limited to 'drivers/tty')
0 files changed, 0 insertions, 0 deletions