From: Kalle Valo <kvalo@codeaurora.org>
To: Brian Norris <briannorris@chromium.org>
Cc: linux-wireless@vger.kernel.org, <linux-kernel@vger.kernel.org>,
Ganapathi Bhat <ganapathi.bhat@nxp.com>,
Nishant Sarmukadam <nishants@marvell.com>,
Amitkumar Karwar <amitkarwar@gmail.com>,
Xinming Hu <huxinming820@gmail.com>,
Arend Van Spriel <arend@broadcom.com>,
Brian Norris <briannorris@chromium.org>
Subject: Re: [PATCH] mwifiex: set needed_headroom, not hard_header_len
Date: Thu, 12 Mar 2020 13:42:10 +0000 (UTC) [thread overview]
Message-ID: <20200312134210.1FC1DC433BA@smtp.codeaurora.org> (raw)
In-Reply-To: <20200227000511.256055-1-briannorris@chromium.org>
Brian Norris <briannorris@chromium.org> wrote:
> hard_header_len provides limitations for things like AF_PACKET, such
> that we don't allow transmitting packets smaller than this.
>
> needed_headroom provides a suggested minimum headroom for SKBs, so that
> we can trivally add our headers to the front.
>
> The latter is the correct field to use in this case, while the former
> mostly just prevents sending small AF_PACKET frames.
>
> In any case, mwifiex already does its own bounce buffering [1] if we
> don't have enough headroom, so hints (not hard limits) are all that are
> needed.
>
> This is the essentially the same bug (and fix) that brcmfmac had, fixed
> in commit cb39288fd6bb ("brcmfmac: use ndev->needed_headroom to reserve
> additional header space").
>
> [1] mwifiex_hard_start_xmit():
> if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN) {
> [...]
> /* Insufficient skb headroom - allocate a new skb */
>
> Fixes: 5e6e3a92b9a4 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> Acked-by: Ganapathi Bhat <ganapathi.gbhat@nxp.com>
Patch applied to wireless-drivers-next.git, thanks.
9454f7a895b8 mwifiex: set needed_headroom, not hard_header_len
--
https://patchwork.kernel.org/patch/11407493/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
prev parent reply other threads:[~2020-03-12 13:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-27 0:05 [PATCH] mwifiex: set needed_headroom, not hard_header_len Brian Norris
2020-03-05 4:00 ` [EXT] " Ganapathi Bhat
2020-03-05 4:37 ` Brian Norris
2020-03-05 6:12 ` Ganapathi Bhat
2020-03-12 13:42 ` Kalle Valo [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=20200312134210.1FC1DC433BA@smtp.codeaurora.org \
--to=kvalo@codeaurora.org \
--cc=amitkarwar@gmail.com \
--cc=arend@broadcom.com \
--cc=briannorris@chromium.org \
--cc=ganapathi.bhat@nxp.com \
--cc=huxinming820@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=nishants@marvell.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;
as well as URLs for NNTP newsgroup(s).