From: Greg KH <gregkh@linuxfoundation.org>
To: Robert Hodaszi <robert.hodaszi@digi.com>
Cc: jirislaby@kernel.org, linux-serial@vger.kernel.org, sherry.sun@nxp.com
Subject: Re: [PATCH] tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A
Date: Thu, 8 Jun 2023 13:52:12 +0200 [thread overview]
Message-ID: <2023060858-groove-riddance-0c09@gregkh> (raw)
In-Reply-To: <20230608111927.1808525-1-robert.hodaszi@digi.com>
On Thu, Jun 08, 2023 at 01:19:27PM +0200, Robert Hodaszi wrote:
> LS1028A is using DMA with LPUART. Having RX watermark set to 1, means
> DMA transactions are started only after receiving the second character.
>
> On other platforms with newer LPUART IP, Receiver Idle Empty function
> initiates the DMA request after the receiver is idling for 4 characters.
> But this feature is missing on LS1028A, which is causing a 1-character
> delay in the RX direction on this platform.
>
> Set RX watermark to 0 to initiate RX DMA after each character.
>
> Signed-off-by: Robert Hodaszi <robert.hodaszi@digi.com>
What commit id does this fix? Should it go to stable releases?
thanks,
greg k-h
next prev parent reply other threads:[~2023-06-08 11:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-08 11:19 [PATCH] tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A Robert Hodaszi
2023-06-08 11:52 ` Greg KH [this message]
2023-06-08 12:22 ` Robert Hodaszi
2023-06-08 15:56 ` Ilpo Järvinen
2023-06-09 12:14 ` Robert Hodaszi
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=2023060858-groove-riddance-0c09@gregkh \
--to=gregkh@linuxfoundation.org \
--cc=jirislaby@kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=robert.hodaszi@digi.com \
--cc=sherry.sun@nxp.com \
/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