From: Robin Gong <yibin.gong@nxp.com>
To: Adam Ford <aford173@gmail.com>, Shawn Guo <shawnguo@kernel.org>
Cc: arm-soc <linux-arm-kernel@lists.infradead.org>,
Rob Herring <robh+dt@kernel.org>,
Sascha Hauer <s.hauer@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Fabio Estevam <festevam@gmail.com>,
dl-linux-imx <linux-imx@nxp.com>,
devicetree <devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH 1/2] arm64: dts: imx8mn: Add spba1 bus
Date: Tue, 11 May 2021 12:20:42 +0000 [thread overview]
Message-ID: <VE1PR04MB6688CD4AA4826EEEBBA2651689539@VE1PR04MB6688.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <CAHCN7xLFpL=9BF9M5gUA6sMhc2ZZMNz+GP0OLmLfpJAWdD7W-w@mail.gmail.com>
On 2021/05/11 18:45 Adam Ford <aford173@gmail.com> wrote:
> > Also may I ask if you have a real use case for this bus node?
>
> The reference manual shows the SPBA bus tells the DMA controller which
> peripherals are associated with it. Nearly all the i.MX boards use this. The
> boards I support have Bluetooth devices connected to a UART running high
> speeds, and if the DMA driver isn't loaded, I can see a performance change.
Compare PIO with DMA on UART, but not w/o this 'spba bus node ' patch?
> In fact, if the DMA firmware isn't loaded, I often get transfer errors.
UART use SDMA ROM firmware instead of RAM firmware, so it should work
even without sdma RAM firmware loaded. Still curious what really happen in
your board without this patch.
next prev parent reply other threads:[~2021-05-11 12:20 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-06 1:33 [PATCH 1/2] arm64: dts: imx8mn: Add spba1 bus Adam Ford
2021-04-06 1:33 ` [PATCH 2/2] arm64: dts: imx8mm: Add spba1 and spba2 buses Adam Ford
2021-05-11 2:46 ` [PATCH 1/2] arm64: dts: imx8mn: Add spba1 bus Shawn Guo
2021-05-11 10:45 ` Adam Ford
2021-05-11 12:20 ` Robin Gong [this message]
2021-05-11 14:48 ` Adam Ford
2021-05-13 2:09 ` Shawn Guo
2021-05-14 14:57 ` Robin Gong
2021-05-14 15:27 ` Adam Ford
2021-05-17 1:35 ` Robin Gong
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=VE1PR04MB6688CD4AA4826EEEBBA2651689539@VE1PR04MB6688.eurprd04.prod.outlook.com \
--to=yibin.gong@nxp.com \
--cc=aford173@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=festevam@gmail.com \
--cc=kernel@pengutronix.de \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=s.hauer@pengutronix.de \
--cc=shawnguo@kernel.org \
/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).