All of lore.kernel.org
 help / color / mirror / Atom feed
From: Johannes Berg <johannes@sipsolutions.net>
To: "Heiner Kallweit" <hkallweit1@gmail.com>,
	"Pali Rohár" <pali@kernel.org>, "Jonas Dreßler" <verdre@v0yd.nl>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
	Amitkumar Karwar <amitkarwar@gmail.com>,
	Ganapathi Bhat <ganapathi017@gmail.com>,
	Xinming Hu <huxinming820@gmail.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Tsuchiya Yuto <kitakar@gmail.com>,
	"open list:TI WILINK WIRELES..." <linux-wireless@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-pci <linux-pci@vger.kernel.org>,
	Maximilian Luz <luzmaximilian@gmail.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH 1/2] mwifiex: Use non-posted PCI register writes
Date: Wed, 01 Sep 2021 19:07:58 +0200	[thread overview]
Message-ID: <f293c619399ba8bd60240879a20ee34db1248255.camel@sipsolutions.net> (raw)
In-Reply-To: <985049b8-bad7-6f18-c94f-368059dd6f95@gmail.com>

On Wed, 2021-09-01 at 18:51 +0200, Heiner Kallweit wrote:
> On 01.09.2021 17:51, Pali Rohár wrote:
> > On Wednesday 01 September 2021 16:01:54 Jonas Dreßler wrote:
> > > On 8/30/21 2:49 PM, Andy Shevchenko wrote:
> > > > On Mon, Aug 30, 2021 at 3:38 PM Jonas Dreßler <verdre@v0yd.nl> wrote:
> > > > > 
> > > > > On the 88W8897 card it's very important the TX ring write pointer is
> > > > > updated correctly to its new value before setting the TX ready
> > > > > interrupt, otherwise the firmware appears to crash (probably because
> > > > > it's trying to DMA-read from the wrong place).
> > > > > 
> 
> This sounds somehow like the typical case where you write DMA descriptors
> and then ring the doorbell. This normally requires a dma_wmb().
> Maybe something like that is missing here?

But it looks like this "TX ring write pointer" is actually the register?

However, I would agree that doing it in mwifiex_write_reg() is possibly
too big a hammer - could be done only for reg->tx_wrptr, not all the
registers?

Actually, can two writes actually cross on PCI?

johannes


  reply	other threads:[~2021-09-01 17:08 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-30 12:37 [PATCH 0/2] mwifiex: Work around firmware bugs on 88W8897 chip Jonas Dreßler
2021-08-30 12:37 ` [PATCH 1/2] mwifiex: Use non-posted PCI register writes Jonas Dreßler
2021-08-30 12:49   ` Andy Shevchenko
2021-09-01 14:01     ` Jonas Dreßler
2021-09-01 15:47       ` Andy Shevchenko
2021-09-01 15:51       ` Pali Rohár
2021-09-01 16:51         ` Heiner Kallweit
2021-09-01 17:07           ` Johannes Berg [this message]
2021-09-01 19:07             ` Heiner Kallweit
2021-09-01 22:41             ` Bjorn Helgaas
2021-09-02 14:05               ` Bjorn Helgaas
2021-09-01 19:40   ` Brian Norris
2021-09-01 20:40     ` Andy Shevchenko
2021-09-01 21:04       ` Brian Norris
2021-09-01 21:07         ` Brian Norris
2021-09-18  7:37           ` Jonas Dreßler
2021-09-20 17:48             ` Brian Norris
2021-09-22 12:50               ` Jonas Dreßler
2021-09-23 15:28                 ` Jonas Dreßler
2021-09-23 19:37                   ` Andy Shevchenko
2021-09-23 19:41                   ` Andy Shevchenko
2021-09-23 20:22                     ` Pali Rohár
2021-09-30 15:38                       ` Jonas Dreßler
2021-09-30 15:42                         ` Pali Rohár
2021-09-30 16:14                           ` Jonas Dreßler
2021-09-30 16:19                             ` Pali Rohár
2021-09-30 16:22                               ` Jonas Dreßler
2021-09-30 16:39                                 ` Pali Rohár
2021-08-30 12:37 ` [PATCH 2/2] mwifiex: Try waking the firmware until we get an interrupt Jonas Dreßler
2021-08-30 12:51   ` Andy Shevchenko
2021-08-30 12:55     ` Andy Shevchenko
2021-09-25 17:32 ` [PATCH 0/2] mwifiex: Work around firmware bugs on 88W8897 chip Pali Rohár

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=f293c619399ba8bd60240879a20ee34db1248255.camel@sipsolutions.net \
    --to=johannes@sipsolutions.net \
    --cc=amitkarwar@gmail.com \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=andy.shevchenko@gmail.com \
    --cc=bhelgaas@google.com \
    --cc=davem@davemloft.net \
    --cc=ganapathi017@gmail.com \
    --cc=hkallweit1@gmail.com \
    --cc=huxinming820@gmail.com \
    --cc=kitakar@gmail.com \
    --cc=kuba@kernel.org \
    --cc=kvalo@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=luzmaximilian@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=pali@kernel.org \
    --cc=verdre@v0yd.nl \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.