From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH 2/2] spi: pxa2xx: use a module softdep for dw_dmac Date: Wed, 10 Apr 2019 16:28:20 +0100 Message-ID: <20190410152820.GT6106@sirena.org.uk> References: <1554900696-28858-1-git-send-email-f.suligoi@asem.it> <1554900696-28858-2-git-send-email-f.suligoi@asem.it> <20190410125612.GR6106@sirena.org.uk> <6eeaf42f4d3f42c58546c429194213b8@asem.it> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="wiiWofWi8Et/oezL" Cc: Daniel Mack , Haojian Zhuang , Robert Jarzmik , "linux-arm-kernel@lists.infradead.org" , "linux-spi@vger.kernel.org" , "linux-kernel@vger.kernel.org" To: Flavio Suligoi Return-path: Content-Disposition: inline In-Reply-To: <6eeaf42f4d3f42c58546c429194213b8@asem.it> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org --wiiWofWi8Et/oezL Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 10, 2019 at 02:05:38PM +0000, Flavio Suligoi wrote: > Hi Mark, > > While this isn't going to hurt anything and might actually help so it's > > fine doesn't this also suggest that there's an issue with deferred probe > > going on as well? > I think that the problem could be related to how the DMA channel is reque= sted. > At the moment the function used are: > pxa2xx_spi_dma_setup --> dma_request_slave_channel_compat --> > --> __dma_request_slave_channel_compat --> dma_request_slave_channel --> > --> dma_request_chan > Actually the final function "dma_request_chan" return > the channel number or "-EPROBE_DEFER" if it's not ready. > But this information ("-EPROBE_DEFER") is lost in the penultimate functio= n=20 > "dma_request_slave_channel", which return only the chann, if all is ok, or > NULL, in case of errors. > So the deferral mechanism is not used. Right, yes - that analysis seems correct. The interfaces seem a bit weird here but fixing them looks like the most complete and robust fix. --wiiWofWi8Et/oezL Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlyuC5QACgkQJNaLcl1U h9AzTQf/R/KL3VH0zEc0hVwvrBj1cDrGwBjBmXW9R97WwaXIq1RcLAJp9jazopLd siILLz9Fl/KtflQ3YgkgdyizttANuiXYEf0PSWMzeTkUXlaIcIrKYjrMPZtpvCZi crpQq730PNf3sbtH+AqNQl1Dgo2LO82hsNekA4irONWIKNRP6EUyccd5BtcbUdp3 AQUEAd1EDYeOKFI8EHbY4GBHu9hN53Bak1CBmd5y3LsA9P5jfA7dsFkGILTTesII DqA0NiLQEcKppgE/IRaK+DmlWXnAk+KKVQOho+QWcQz/PvyrEg62r8c7GsRo2dFe C8YNkpxNhOcXxCPou5xpMwPjQNF46g== =TuEH -----END PGP SIGNATURE----- --wiiWofWi8Et/oezL-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6DFCC282DE for ; 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Wed, 10 Apr 2019 16:28:20 +0100 (BST) Date: Wed, 10 Apr 2019 16:28:20 +0100 From: Mark Brown To: Flavio Suligoi Subject: Re: [PATCH 2/2] spi: pxa2xx: use a module softdep for dw_dmac Message-ID: <20190410152820.GT6106@sirena.org.uk> References: <1554900696-28858-1-git-send-email-f.suligoi@asem.it> <1554900696-28858-2-git-send-email-f.suligoi@asem.it> <20190410125612.GR6106@sirena.org.uk> <6eeaf42f4d3f42c58546c429194213b8@asem.it> MIME-Version: 1.0 In-Reply-To: <6eeaf42f4d3f42c58546c429194213b8@asem.it> X-Cookie: teamwork, n.: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190410_082826_971922_8C3E15D6 X-CRM114-Status: GOOD ( 13.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "linux-kernel@vger.kernel.org" , Haojian Zhuang , "linux-spi@vger.kernel.org" , Daniel Mack , Robert Jarzmik , "linux-arm-kernel@lists.infradead.org" Content-Type: multipart/mixed; boundary="===============7465888703738063558==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============7465888703738063558== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="wiiWofWi8Et/oezL" Content-Disposition: inline --wiiWofWi8Et/oezL Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Apr 10, 2019 at 02:05:38PM +0000, Flavio Suligoi wrote: > Hi Mark, > > While this isn't going to hurt anything and might actually help so it's > > fine doesn't this also suggest that there's an issue with deferred probe > > going on as well? > I think that the problem could be related to how the DMA channel is reque= sted. > At the moment the function used are: > pxa2xx_spi_dma_setup --> dma_request_slave_channel_compat --> > --> __dma_request_slave_channel_compat --> dma_request_slave_channel --> > --> dma_request_chan > Actually the final function "dma_request_chan" return > the channel number or "-EPROBE_DEFER" if it's not ready. > But this information ("-EPROBE_DEFER") is lost in the penultimate functio= n=20 > "dma_request_slave_channel", which return only the chann, if all is ok, or > NULL, in case of errors. > So the deferral mechanism is not used. Right, yes - that analysis seems correct. The interfaces seem a bit weird here but fixing them looks like the most complete and robust fix. --wiiWofWi8Et/oezL Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlyuC5QACgkQJNaLcl1U h9AzTQf/R/KL3VH0zEc0hVwvrBj1cDrGwBjBmXW9R97WwaXIq1RcLAJp9jazopLd siILLz9Fl/KtflQ3YgkgdyizttANuiXYEf0PSWMzeTkUXlaIcIrKYjrMPZtpvCZi crpQq730PNf3sbtH+AqNQl1Dgo2LO82hsNekA4irONWIKNRP6EUyccd5BtcbUdp3 AQUEAd1EDYeOKFI8EHbY4GBHu9hN53Bak1CBmd5y3LsA9P5jfA7dsFkGILTTesII DqA0NiLQEcKppgE/IRaK+DmlWXnAk+KKVQOho+QWcQz/PvyrEg62r8c7GsRo2dFe C8YNkpxNhOcXxCPou5xpMwPjQNF46g== =TuEH -----END PGP SIGNATURE----- --wiiWofWi8Et/oezL-- --===============7465888703738063558== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============7465888703738063558==--