diff mbox series

[3/3,RFC] ARM: shmobile: defconfig: Disable PL310_ERRATA_588369

Message ID 20190821124602.29317-4-geert+renesas@glider.be (mailing list archive)
State Under Review
Delegated to: Geert Uytterhoeven
Headers show
Series soc: renesas: ARM errata updates | expand

Commit Message

Geert Uytterhoeven Aug. 21, 2019, 12:46 p.m. UTC
PL310 Erratum 588369 affects PL310 cache controller revisions older than
r2p0.

As Renesas ARM SoCs contain the following revisions:
  - SH-Mobile AG5: r3p1,
  - R-Mobile A1: r3p1-50rel0,
  - R-Car H1: r3p2,
  - RZ/A1: r3p2,
  - RZ/A2: r3p3,
none of them are affected, and support for the errata can be disabled
safely.

The EMMA Mobile EV2 documentation doesn't mention the revision of its
PL310 cache controller, so this SoC might be affected.  However, the L2
cache controller is not enabled by Linux.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 arch/arm/configs/shmobile_defconfig | 1 -
 1 file changed, 1 deletion(-)

Comments

Simon Horman Aug. 22, 2019, 8:58 a.m. UTC | #1
On Wed, Aug 21, 2019 at 02:46:02PM +0200, Geert Uytterhoeven wrote:
> PL310 Erratum 588369 affects PL310 cache controller revisions older than
> r2p0.
> 
> As Renesas ARM SoCs contain the following revisions:
>   - SH-Mobile AG5: r3p1,
>   - R-Mobile A1: r3p1-50rel0,
>   - R-Car H1: r3p2,
>   - RZ/A1: r3p2,
>   - RZ/A2: r3p3,
> none of them are affected, and support for the errata can be disabled
> safely.
> 
> The EMMA Mobile EV2 documentation doesn't mention the revision of its
> PL310 cache controller, so this SoC might be affected.  However, the L2
> cache controller is not enabled by Linux.

If the controller is not enabled by Linux then I would think that the
Errata is not needed. If that is true then I agree with this patch.

Regarding making assumptions about the version of the PL310 cache
controller, I suggest that we cannot assume that it is not affected
without further information.

> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  arch/arm/configs/shmobile_defconfig | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/arm/configs/shmobile_defconfig b/arch/arm/configs/shmobile_defconfig
> index 123821e63873dafa..95a127cbe8e6fcd7 100644
> --- a/arch/arm/configs/shmobile_defconfig
> +++ b/arch/arm/configs/shmobile_defconfig
> @@ -8,7 +8,6 @@ CONFIG_CC_OPTIMIZE_FOR_SIZE=y
>  CONFIG_PERF_EVENTS=y
>  CONFIG_SLAB=y
>  CONFIG_ARCH_RENESAS=y
> -CONFIG_PL310_ERRATA_588369=y
>  CONFIG_SMP=y
>  CONFIG_SCHED_MC=y
>  CONFIG_NR_CPUS=8
> -- 
> 2.17.1
>
Geert Uytterhoeven Aug. 23, 2019, 9:49 a.m. UTC | #2
Hi Simon,

On Thu, Aug 22, 2019 at 10:58 AM Simon Horman <horms@verge.net.au> wrote:
> On Wed, Aug 21, 2019 at 02:46:02PM +0200, Geert Uytterhoeven wrote:
> > PL310 Erratum 588369 affects PL310 cache controller revisions older than
> > r2p0.
> >
> > As Renesas ARM SoCs contain the following revisions:
> >   - SH-Mobile AG5: r3p1,
> >   - R-Mobile A1: r3p1-50rel0,
> >   - R-Car H1: r3p2,
> >   - RZ/A1: r3p2,
> >   - RZ/A2: r3p3,
> > none of them are affected, and support for the errata can be disabled
> > safely.
> >
> > The EMMA Mobile EV2 documentation doesn't mention the revision of its
> > PL310 cache controller, so this SoC might be affected.  However, the L2
> > cache controller is not enabled by Linux.
>
> If the controller is not enabled by Linux then I would think that the
> Errata is not needed. If that is true then I agree with this patch.
>
> Regarding making assumptions about the version of the PL310 cache
> controller, I suggest that we cannot assume that it is not affected
> without further information.

I agree, so this needs more investigation.

It seems this was included in shmobile_defconfig based on the old
armadillo800eav_defconfig, which enabled several errata options since
commit e0ef0984ae346c54 ("ARM: shmobile: armadillo800eva: enable all
errata for cache on defconfig").
Based on my current knowledge, PL310_ERRATA_769419 is the only one that
affects Renesas SoCs (ignoring EMEV2 for now) with a PL310, and thus
should be enabled, too.

Gr{oetje,eeting}s,

                        Geert
diff mbox series

Patch

diff --git a/arch/arm/configs/shmobile_defconfig b/arch/arm/configs/shmobile_defconfig
index 123821e63873dafa..95a127cbe8e6fcd7 100644
--- a/arch/arm/configs/shmobile_defconfig
+++ b/arch/arm/configs/shmobile_defconfig
@@ -8,7 +8,6 @@  CONFIG_CC_OPTIMIZE_FOR_SIZE=y
 CONFIG_PERF_EVENTS=y
 CONFIG_SLAB=y
 CONFIG_ARCH_RENESAS=y
-CONFIG_PL310_ERRATA_588369=y
 CONFIG_SMP=y
 CONFIG_SCHED_MC=y
 CONFIG_NR_CPUS=8