netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Jiawen Wu" <jiawenwu@trustnetic.com>
To: "'Russell King \(Oracle\)'" <linux@armlinux.org.uk>
Cc: <netdev@vger.kernel.org>
Subject: RE: Bug? xpcs-wx: read-modify-write to different registers?
Date: Mon, 23 Sep 2024 18:12:44 +0800	[thread overview]
Message-ID: <01ee01db0da1$2196ac60$64c40520$@trustnetic.com> (raw)
In-Reply-To: <ZvEyZGKt5elazWfj@shell.armlinux.org.uk>



> -----Original Message-----
> From: Russell King (Oracle) <linux@armlinux.org.uk>
> Sent: Monday, September 23, 2024 5:18 PM
> To: Jiawen Wu <jiawenwu@trustnetic.com>
> Cc: netdev@vger.kernel.org
> Subject: Bug? xpcs-wx: read-modify-write to different registers?
> 
> Hi,
> 
> While making some cleanups to the XPCS driver, I spotted the following
> in pcs-xpcs-wx.c:
> 
>         val = txgbe_read_pma(xpcs, TXGBE_RX_GEN_CTL3);
>         val = u16_replace_bits(val, 0x4, TXGBE_RX_GEN_CTL3_LOS_TRSHLD0);
>         txgbe_write_pma(xpcs, TXGBE_RX_EQ_ATTN_CTL, val);
> 
> This reads from the TXGBE_RX_GEN_CTL3 register, changes a value in a
> field, and then writes it back to a different register,
> TXGBE_RX_EQ_ATTN_CTL. This doesn't look correct.
> 
> Please check whether this code is correct, if not please submit a fix.
> 
> Thanks.

OMG, it's a real bug. Register TXGBE_RX_GEN_CTL3 should be written back.

Thanks Russell, I'll send a patch to fix it.



      reply	other threads:[~2024-09-23 10:13 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-23  9:18 Bug? xpcs-wx: read-modify-write to different registers? Russell King (Oracle)
2024-09-23 10:12 ` Jiawen Wu [this message]

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='01ee01db0da1$2196ac60$64c40520$@trustnetic.com' \
    --to=jiawenwu@trustnetic.com \
    --cc=linux@armlinux.org.uk \
    --cc=netdev@vger.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).