On Thu, Jul 04, 2013 at 06:02:50PM +0200, Uwe Kleine-König wrote: > Hi Greg, > > On Thu, Jul 04, 2013 at 08:58:36AM -0700, Greg Kroah-Hartman wrote: > > On Thu, Jul 04, 2013 at 11:27:16AM +0200, Uwe Kleine-König wrote: > > > On Fri, Jun 28, 2013 at 11:49:41AM +0200, Uwe Kleine-König wrote: > > > > Without this patch the driver waits ~1 ms for the UART to become idle. At > > > > 115200n8 this time is (theoretically) enough to transfer 11.5 characters > > > > (= 115200 bits/s / (10 Bits/char) * 1ms). As the mxs-auart has a fifo size > > > > of 16 characters the clock is gated too early. The problem is worse for > > > > lower baud rates. > > > > > > > > This only happens to really shut down the transmitter in the middle of a > > > > transfer if /dev/ttyAPPx isn't opened in userspace (e.g. by a getty) but > > > > was at least once (because the bootloader doesn't disable the transmitter). > > > > > > > > So increase the timeout to 20 ms which should be enough for 9600n8, too. > > > > Moreover skip gating the clock if the timeout is elapsed. > > > > > > > > Cc: stable@xxxxxxxxxxxxxxx # v2.6.39+ > > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > > > Any comments on this. I hoped this patch would make it in for 3.10 :-( > > > > You sent it after my tree closed for 3.11, 3.10 is a stretch :) > You close your tree for fixes? 2 days before the kernel is to be released? Yes, I do. This will get into 3.11-rc2 or -rc3, and backported to 3.10 and others, so please just give it a bit of time. It's just a driver issue, nothing keeping machines from booting properly :) thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
