From mboxrd@z Thu Jan 1 00:00:00 1970 From: h.grohne@intenta.de (Helmut Grohne) Date: Mon, 4 Jun 2018 12:21:56 +0200 Subject: [PATCH v3 0/3] serial: xuartps: hardware race condition and cleanup Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The character transmission in xuartps is racy. If the transmitter is disabled early, the device is confused and produces a desync. Garbage on the remote end can be a visible symptom. The second patch in this series tries to reduce that race condition in accordance with the hardware documentation, but it cannot remove it entirely. The first and third patches are code cleanup. Changes since v2: * Do not attempt to disable the transmitter after a transmission (original behaviour around 3.14). These patches no longer touch with the transmitter state at all as requested by S?ren Brinkmann. * Add Acked-by/Reviewed-by tags from S?ren Brinkmann after addressing his remarks. Earlier patches/discussion at: https://www.spinics.net/lists/linux-serial/msg23145.html https://www.spinics.net/lists/linux-serial/msg23156.html https://www.spinics.net/lists/linux-serial/msg23157.html Helmut Grohne (3): serial: xuartps: fix typo in cdns_uart_startup serial: xuartps: reduce hardware TX race condition serial: xuartps: remove unnecessary register write drivers/tty/serial/xilinx_uartps.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) -- 2.11.0