Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755627AbbGVFNo (ORCPT ); Wed, 22 Jul 2015 01:13:44 -0400 Received: from mail-ig0-f173.google.com ([209.85.213.173]:36295 "EHLO mail-ig0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753815AbbGVFNm (ORCPT ); Wed, 22 Jul 2015 01:13:42 -0400 Date: Wed, 22 Jul 2015 00:13:34 -0500 From: Michael Welling To: Sebastian Reichel Cc: Pavel Machek , Pali =?iso-8859-1?Q?Roh=E1r?= , Tony Lindgren , Ivaylo Dimitrov , Aaro Koskinen , Nishanth Menon , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: linux 4.2-rc1 broken Nokia N900 Message-ID: <20150722051334.GA2165@deathstar> References: <201507111405.06048@pali> <201507132234.22082@pali> <20150713215232.GA22584@deathray> <201507140002.44119@pali> <20150713223607.GA23001@deathray> <20150714071412.GA12844@pali> <20150720204647.GA11931@deathstar> <20150721093441.GA23241@amd> <20150722001741.GA7950@deathstar> <20150722020306.GA8379@earth> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150722020306.GA8379@earth> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3549 Lines: 105 On Wed, Jul 22, 2015 at 04:03:07AM +0200, Sebastian Reichel wrote: > Hi, > > On Tue, Jul 21, 2015 at 07:17:41PM -0500, Michael Welling wrote: > > On Tue, Jul 21, 2015 at 11:34:41AM +0200, Pavel Machek wrote: > > > > This code has my head spinning. > > > > I found that the errors do not occur when the driver is built into the kernel. > > > > I also found that with the patch below the errors go away. > > > > Not sure if it is acceptible but see if it fixes things on your side. > > > > > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > > index cf8b91b..3164d13 100644 > > --- a/drivers/spi/spi.c > > +++ b/drivers/spi/spi.c > > @@ -1801,11 +1801,11 @@ int spi_setup(struct spi_device *spi) > > if (!spi->max_speed_hz) > > spi->max_speed_hz = spi->master->max_speed_hz; > > > > - spi_set_cs(spi, false); > > - > > if (spi->master->setup) > > status = spi->master->setup(spi); > > > > + spi_set_cs(spi, false); > > + > > dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", > > (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), > > (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", > > mh. maybe a runtime PM issue? mh? > > * external abort on non-linefetch: address cannot be accessed, > since the module's clocks are disabled > * built-in works, module not: built-in is probably a little bit > faster (module must not be loaded from filesystem), so that > the device has not yet been suspended > * Before 4.2, omap2_mcspi_set_cs() was called in the setup > routine, which acquired runtime PM > * In 4.2, omap2_mcspi_set_cs() seems to be called without a > prior pm_runtime_get_sync() > * With your workaround, the device has not yet returned to > suspend after the runtime PM acquisition in setup() > > So I suggest trying the following (compile tested only) patch: > It seems you are right. With this patch the SPI drivers no longer cause data aborts. I will wait for feedback from Pavel and Pali but it looks like we have a winner. > -- Sebastian > > diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c > index 5867384..f7d9ffd 100644 > --- a/drivers/spi/spi-omap2-mcspi.c > +++ b/drivers/spi/spi-omap2-mcspi.c > @@ -245,6 +245,7 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) > > static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) > { > + struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); > u32 l; > > /* The controller handles the inverted chip selects > @@ -255,6 +256,8 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) > enable = !enable; > > if (spi->controller_state) { > + pm_runtime_get_sync(mcspi->dev); > + Should the return code should be checked here as with the other instances of pm_runtime_get_sync? > l = mcspi_cached_chconf0(spi); > > if (enable) > @@ -263,6 +266,9 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) > l |= OMAP2_MCSPI_CHCONF_FORCE; > > mcspi_write_chconf0(spi, l); > + > + pm_runtime_mark_last_busy(mcspi->dev); > + pm_runtime_put_autosuspend(mcspi->dev); > } > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/