Re: linux 4.2-rc1 broken Nokia N900

From: Michael Welling <mwelling@ieee.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: "Pali Rohár" <pali.rohar@gmail.com>,
	"Sebastian Reichel" <sre@kernel.org>,
	"Tony Lindgren" <tony@atomide.com>,
	"Ivaylo Dimitrov" <ivo.g.dimitrov.75@gmail.com>,
	"Aaro Koskinen" <aaro.koskinen@iki.fi>,
	"Nishanth Menon" <nm@ti.com>,
	linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: linux 4.2-rc1 broken Nokia N900
Date: Tue, 14 Jul 2015 15:17:22 -0500	[thread overview]
Message-ID: <20150714201722.GA31356@deathray> (raw)
In-Reply-To: <20150714200125.GA26147@amd>

On Tue, Jul 14, 2015 at 10:01:26PM +0200, Pavel Machek wrote:
> On Tue 2015-07-14 11:33:42, Michael Welling wrote:
> > On Tue, Jul 14, 2015 at 09:14:12AM +0200, Pali Rohár wrote:
> > > On Monday 13 July 2015 17:36:07 Michael Welling wrote:
> > > > On Tue, Jul 14, 2015 at 12:02:44AM +0200, Pali Rohár wrote:
> > > > > I think nothing special. I just call:
> > > > > 
> > > > > export ARCH=arm
> > > > > export CROSS_COMPILE=arm-linux-gnueabi-
> > > > > make rx51_defconfig
> > > > > rm -f arch/arm/boot/zImage
> > > > > make -j12 zImage modules omap3-n900.dtb CONFIG_DEBUG_SECTION_MISMATCH=y
> > > > > cat arch/arm/boot/zImage arch/arm/boot/dts/omap3-n900.dtb > arch/arm/boot/zImage.new
> > > > > mv arch/arm/boot/zImage.new arch/arm/boot/zImage
> > > > >
> > > > 
> > > > Where are you getting rx51_defconfig from?
> > > > 
> > > > This does not appear to be in the kernel source any longer.
> > > > 
> > > > Can you try the above with omap2plus_defconfig?
> > > >  
> > > 
> > > It is in my linux-n900 repository: https://github.com/pali/linux-n900
> > > Repository contains more n900 specific patches but SPI code is unpatched
> > > 
> > > https://github.com/pali/linux-n900/blob/HEAD/arch/arm/configs/rx51_defconfig
> > > 
> > > Later in week I can try to compile also with omap2plus_defconfig...
> > > But in my opinion kernel should not crash with different configuration.
> > 
> > True.
> > 
> > Could you try the following change to the set_cs function and see if
> >it helps.
> 
> Ok, so:
> 
> 4.2-rc1 worked for me, IIRC.

This does not make sense.

Nothing has changed in drivers/spi between these versions.

Are you sure that 4.2-rc1 worked for you?

> 
> 4.2-rc2 oopses a lot.
> 
> 4.2-rc2+ this patch oopses, too. I don't have serial console, so it is
> hard to tell if it is the same oops.
> 
> 									Pavel
> 
> > diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
> > index 5867384..666038b 100644
> > --- a/drivers/spi/spi-omap2-mcspi.c
> > +++ b/drivers/spi/spi-omap2-mcspi.c
> > @@ -245,16 +245,18 @@ 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_cs *cs = spi->controller_state;
> >  	u32 l;
> >  
> > -	/* The controller handles the inverted chip selects
> > -	 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
> > -	 * the inversion from the core spi_set_cs function.
> > -	 */
> > -	if (spi->mode & SPI_CS_HIGH)
> > -		enable = !enable;
> > +	if (cs) {
> > +
> -- 
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html