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| author | Paul Walmsley <paul@pwsan.com> | 2012-01-26 06:50:56 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-02-03 01:00:16 +0400 |
| commit | 6bbcbf22085e0b144899d6067e243dd26c0e7533 (patch) | |
| tree | 5b604b1ca6fd4ca140dc1a1ca0f800dc430671f6 /samples | |
| parent | edbe5dbefe5b514d094558ab59c8dc7578e117dd (diff) | |
| download | linux-6bbcbf22085e0b144899d6067e243dd26c0e7533.tar.xz | |
tty: serial: omap-serial: wakeup latency constraint is in microseconds, not milliseconds
The receive FIFO wakeup latency estimate in the omap-serial driver is
three orders of magnitude too small. This effectively prevents the
MPU from going to a low-power state when CONFIG_CPU_IDLE=y. This is a
major power management regression and masks some other FIFO-related
bugs in the driver.
Fix by correcting the most egregious problem in the RX wakeup latency
estimate. There are several other flaws in the estimator; these will
be fixed by a separate patch series intended for 3.4.
The difference in low-power states with this patch can be observed via
debugfs in pm_debug/count.
This estimate does not have any effect when CONFIG_CPU_IDLE=n.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'samples')
0 files changed, 0 insertions, 0 deletions