From 23d782ea98013f8d0c96233a720e9373ff741648 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 28 Jun 2013 11:49:41 +0200 Subject: [PATCH] serial/mxs-auart: increase time to wait for transmitter to become idle MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 079a036f4283e2b0e5c26080b8c5112bc0cc1831 upstream. 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. Signed-off-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- Reading git-format-patch failed