This is a note to let you know that I've just added the patch titled
serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake
to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 7090abd6ad0610a144523ce4ffcb8560909bf2a8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= ilpo.jarvinen@linux.intel.com Date: Tue, 8 Nov 2022 14:19:51 +0200 Subject: serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Configure DMA to use 16B burst size with Elkhart Lake. This makes the bus use more efficient and works around an issue which occurs with the previously used 1B.
The fix was initially developed by Srikanth Thokala and Aman Kumar. This together with the previous config change is the cleaned up version of the original fix.
Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: stable@vger.kernel.org # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu wentong.wu@intel.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/tty/serial/8250/8250_lpss.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 7d9cddbfef40..0e43bdfb7459 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -174,6 +174,8 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) */ up->dma = dma;
+ lpss->dma_maxburst = 16; + port->set_termios = dw8250_do_set_termios;
return 0;