All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Mark Brown <broonie@kernel.org>
Cc: kernel@pengutronix.de, linux-spi@vger.kernel.org
Subject: Re: [PATCH 1/2] spi: Make spi_add_lock a per-controller lock
Date: Wed, 13 Oct 2021 18:10:33 +0200	[thread overview]
Message-ID: <20211013161033.yrquwcgwzqxwfszo@pengutronix.de> (raw)
In-Reply-To: <YWb5gUxgdiczqV5Q@sirena.org.uk>

[-- Attachment #1: Type: text/plain, Size: 1218 bytes --]

Hello Mark,

On Wed, Oct 13, 2021 at 04:21:37PM +0100, Mark Brown wrote:
> On Wed, Oct 13, 2021 at 03:37:09PM +0200, Uwe Kleine-König wrote:
> > The spi_add_lock that is removed with this change was held when
> > spi_add_device() called device_add() (via __spi_add_device()).
> > 
> > In the case where the added device is an spi-mux calling device_add()
> > might result in calling the spi-mux's probe function which adds another
> > controller and for that spi_add_device() might be called. This results
> > in a dead-lock.
> > 
> > To circumvent this deadlock replace the global spi_add_lock with a lock
> > per controller.
> > 
> > The biggest part of this patch was authored by Mark Brown.
> 
> I'll go ahead with my copy of this (partly as I've already got it
> ready queued).

That's what I expected, I just sent it that the base for patch 2 is
properly available e.g. for the autobuilders. Did you modify your patch
since you sent it? If you resend or apply to your tree I can rebase
patch 2 on top of it.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

  reply	other threads:[~2021-10-13 16:10 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-13 13:37 [PATCH 1/2] spi: Make spi_add_lock a per-controller lock Uwe Kleine-König
2021-10-13 13:37 ` [PATCH 2/2] spi-mux: Fix false-positive lockdep splats Uwe Kleine-König
2021-10-13 15:21 ` [PATCH 1/2] spi: Make spi_add_lock a per-controller lock Mark Brown
2021-10-13 16:10   ` Uwe Kleine-König [this message]
2021-10-13 17:22     ` Mark Brown
2021-10-14 13:18 ` (subset) " Mark Brown

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=20211013161033.yrquwcgwzqxwfszo@pengutronix.de \
    --to=u.kleine-koenig@pengutronix.de \
    --cc=broonie@kernel.org \
    --cc=kernel@pengutronix.de \
    --cc=linux-spi@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 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.