From: Lukasz Majewski <lukma@denx.de>
To: linux-kernel@vger.kernel.org, Shawn Guo <shawnguo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
devicetree@vger.kernel.org, Sascha Hauer <s.hauer@pengutronix.de>,
Lukasz Majewski <lukma@denx.de>, Stefan Agner <stefan@agner.ch>,
Rob Herring <robh+dt@kernel.org>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] dts: Disable DMA support on the BK4 vf610 device's fsl_lpuart driver
Date: Thu, 10 Oct 2019 11:08:02 +0200 [thread overview]
Message-ID: <20191010090802.16383-1-lukma@denx.de> (raw)
This change disables the DMA support (RX/TX) on the NXP's fsl_lpuart
driver - the PIO mode is used instead. This change is necessary for better
robustness of BK4's device use cases with many potentially interrupted
short serial transfers.
Without it the driver hangs when some distortion happens on UART lines.
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
---
Changes for v2:
- Use /delete-property/dma-names; instead of dma-names = "","";
---
arch/arm/boot/dts/vf610-bk4.dts | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm/boot/dts/vf610-bk4.dts b/arch/arm/boot/dts/vf610-bk4.dts
index 0f3870d3b099..830c85476b3d 100644
--- a/arch/arm/boot/dts/vf610-bk4.dts
+++ b/arch/arm/boot/dts/vf610-bk4.dts
@@ -259,24 +259,28 @@
&uart0 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart0>;
+ /delete-property/dma-names;
status = "okay";
};
&uart1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart1>;
+ /delete-property/dma-names;
status = "okay";
};
&uart2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart2>;
+ /delete-property/dma-names;
status = "okay";
};
&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3>;
+ /delete-property/dma-names;
status = "okay";
};
--
2.20.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-10-10 9:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-10 9:08 Lukasz Majewski [this message]
2019-10-25 8:55 ` [PATCH v2] dts: Disable DMA support on the BK4 vf610 device's fsl_lpuart driver Shawn Guo
2019-10-25 10:00 ` Lukasz Majewski
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191010090802.16383-1-lukma@denx.de \
--to=lukma@denx.de \
--cc=devicetree@vger.kernel.org \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=robh+dt@kernel.org \
--cc=robin.murphy@arm.com \
--cc=s.hauer@pengutronix.de \
--cc=shawnguo@kernel.org \
--cc=stefan@agner.ch \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).