This is a note to let you know that I've just added the patch titled
serial: 8250_lpss: Configure DMA also w/o DMA filter
to the 6.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-8250_lpss-configure-dma-also-w-o-dma-filter.patch
and it can be found in the queue-6.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1bfcbe5805d0cfc83c3544dcd01e0a282c1f6790 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Date: Tue, 8 Nov 2022 14:19:50 +0200
Subject: serial: 8250_lpss: Configure DMA also w/o DMA filter
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
commit 1bfcbe5805d0cfc83c3544dcd01e0a282c1f6790 upstream.
If the platform doesn't use DMA device filter (as is the case with
Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This
results in skipping also *_maxburst setup which is undesirable.
Refactor lpss8250_dma_setup() to configure DMA even if filter is not
setup.
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_lpss.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -277,8 +277,13 @@ static int lpss8250_dma_setup(struct lps
struct dw_dma_slave *rx_param, *tx_param;
struct device *dev = port->port.dev;
- if (!lpss->dma_param.dma_dev)
+ if (!lpss->dma_param.dma_dev) {
+ dma = port->dma;
+ if (dma)
+ goto out_configuration_only;
+
return 0;
+ }
rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
if (!rx_param)
@@ -289,16 +294,18 @@ static int lpss8250_dma_setup(struct lps
return -ENOMEM;
*rx_param = lpss->dma_param;
- dma->rxconf.src_maxburst = lpss->dma_maxburst;
-
*tx_param = lpss->dma_param;
- dma->txconf.dst_maxburst = lpss->dma_maxburst;
dma->fn = lpss8250_dma_filter;
dma->rx_param = rx_param;
dma->tx_param = tx_param;
port->dma = dma;
+
+out_configuration_only:
+ dma->rxconf.src_maxburst = lpss->dma_maxburst;
+ dma->txconf.dst_maxburst = lpss->dma_maxburst;
+
return 0;
}
Patches currently in stable-queue which might be from ilpo.jarvinen@xxxxxxxxxxxxxxx are
queue-6.0/serial-8250_lpss-use-16b-dma-burst-with-elkhart-lake.patch
queue-6.0/serial-8250-flush-dma-rx-on-rlsi.patch
queue-6.0/serial-8250_lpss-configure-dma-also-w-o-dma-filter.patch
queue-6.0/serial-8250-fall-back-to-non-dma-rx-if-iir_rdi-occurs.patch
queue-6.0/serial-8250_omap-remove-wait-loop-from-errata-i202-w.patch
