From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Guinot Subject: Re: [1/4] gpio: gpio-f7188x: Use mutex for access serialisation. Date: Thu, 10 Sep 2015 00:01:40 +0200 Message-ID: <20150909220140.GD9892@kw.sim.vm.gnt> References: <1440093809-18234-1-git-send-email-plr.vincent@gmail.com> <7d1a2156ddabe0b72964e88734adba307a472067.1440093298.git.plr.vincent@gmail.com> <20150821175216.GE1729@kw.sim.vm.gnt> <20150821224824.3406caa0@x2> <20150903200540.399a96b8@x2> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="sXc4Kmr5FA7axrvy" Return-path: Received: from vm1.sequanux.org ([188.165.36.56]:41793 "EHLO vm1.sequanux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751829AbbIIVzU (ORCPT ); Wed, 9 Sep 2015 17:55:20 -0400 Content-Disposition: inline In-Reply-To: <20150903200540.399a96b8@x2> Sender: linux-gpio-owner@vger.kernel.org List-Id: linux-gpio@vger.kernel.org To: Vincent Pelletier Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Donnefort , Yoann Sculo --sXc4Kmr5FA7axrvy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 03, 2015 at 08:05:40PM +0200, Vincent Pelletier wrote: > Hi, >=20 > On Fri, 21 Aug 2015 22:48:24 +0200, Vincent Pelletier > wrote: > > On Fri, 21 Aug 2015 19:52:16 +0200, Simon Guinot > > wrote: > > > Please, could you describe a setup (as simple as possible) allowing to > > > reproduce the issue ? I'll try it on my side. > > [...] > > > Please try to make the module list needed to reproduce the issue as > > > short as possible. Ideally only gpio_f7188x would be needed. > >=20 > > The simplest I could find so far needs gpio-input-polled with 20ms > > polling period (I didn't try to change polling period), and a shell loop > > writing to gpioXX/value. >=20 > Have you had a chance to reproduce this issue ? > Can I do something to help ? Hi Vincent, Vincent (Donnefort) finally succeeds to reproduce the issue. The setup is quite simple. You only have to flood the gpio-f7188x driver via the sysfs GPIO interface. Nothing more is needed. After some debugging we discovered that the problem comes from the __request_region function which don't handle very well concurrent requests on a muxed region. I will send a patch as a reply to this email. Please, can you test it ? Thanks, Simon --sXc4Kmr5FA7axrvy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlXwrEQACgkQgtp0PDeOcDql1ACeMW5HqcNP/LVkczwb8ZO3xZcA Hh8AnAt+Y/QXGSakdqycNB6ENggJf90m =yWVS -----END PGP SIGNATURE----- --sXc4Kmr5FA7axrvy--