Re: linux-next: Tree for Aug 31 (new arm, arm64, s390 failures)

[Guenter Roeck]

On 08/31/2015 12:13 PM, Marc Zyngier wrote:
> On Mon, 31 Aug 2015 11:57:14 -0700
> Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> > Hi Marc,
> >
> > On 08/31/2015 11:26 AM, Marc Zyngier wrote:
> > [ ... ]
> > > Actually, the kernel dies because of this:
> > >
> > > commit adaac459759db4a1fd35baddbe47bac700095496
> > > Author: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
> > > Date:   Sun Aug 30 09:33:53 2015 +0200
> > >
> > >       regmap: Introduce max_raw_read/write for regmap_bulk_read/write
> > >
> > >       There are some buses which have a limit on the maximum number of
> > >       bytes that can be send/received. An example for this is
> > >       I2C_FUNC_SMBUS_I2C_BLOCK which does not support any reads/writes of
> > >       more than 32 bytes. The regmap_bulk operations should still be able
> > >       to utilize the full 32 bytes in this case.
> > >
> > >       Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
> > >       Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
> > >
> > > which never considers bus to be NULL in __regmap_init. With the
> > > following patch applied, I can boot to a prompt:
> > >
> > >   From 031eae5a1b34f952ba3dcaecb4eb4ec9d3bda352 Mon Sep 17 00:00:00 2001
> > > From: Marc Zyngier <marc.zyngier@xxxxxxx>
> > > Date: Mon, 31 Aug 2015 19:16:16 +0100
> > > Subject: [PATCH] regmap: Fix max_raw_read/write handling when bus is NULL
> > >
> > > Commit adaac459759d ("regmap: Introduce max_raw_read/write
> > > for regmap_bulk_read/write") added new fields to regmap_bus
> > > and started using them in __regmap_init, but failed to
> > > consider the case where bus would be NULL, like in the
> > > vexpress-syscgf case. The box (actually its qemu version)
> > > ends up dying painfully.
> > >
> > > Fix it by testing bus before doing anything else.
> > >
> > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> >
> > Yes, that fixes the vexpress failures.
> >
> > Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> >
> > However, I still need to revert your patches to get my realview-pb-a8
> > and realview-eb tests to work again.
> >
> > I am a bit concerned about the use of of_address_to_resource(),
> > which can return an error, leaving cpu_res undefined. Also, if
> > both CONFIG_OF and CONFIG_ACPI are not configured, supports_deactivate
> > is set to true by default. This is the configuration used in my
> > failing tests.
> >
> > With that in mind, I ran a simple test.
> >
> > -static struct static_key supports_deactivate = STATIC_KEY_INIT_TRUE;
> > +static struct static_key supports_deactivate = STATIC_KEY_INIT_FALSE;
> >
> > Bingo, problem solved. Can you try to find a clean solution ?
>
> Yeah, I just came to the same conclusion, and to the following patch:
>
>  From 059bc80a4fc433dda99d75a712f30a77ce4964bc Mon Sep 17 00:00:00 2001
> From: Marc Zyngier <marc.zyngier@xxxxxxx>
> Date: Mon, 31 Aug 2015 20:00:35 +0100
> Subject: [PATCH] irqchip/gic: Fix EOImode settiing non-DT/ACPI systems
>
> Non-DT/ACPI systems call directly into the GIC driver at init time.
> Since 0b996fd35957 ("irqchip/GIC: Convert to EOImode == 1"), this
> breaks old non firmware-driven platforms, as the driver only
> works out the capability of the platform on the DT/ACPI paths.
>
> Fix this thinko by forcing EOImode==0 on non-DT platforms,
> which are not capable of supporting a hypervisor anyway.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Yep, that fixes the problem.

Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Thanks,
Guenter

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