Re: [PATCH] ARM: tegra20: Store CPU "resettable" status in IRAM

From: Thierry Reding
Date: Mon Jan 19 2015 - 09:12:36 EST


On Thu, Jan 15, 2015 at 01:58:57PM +0300, Dmitry Osipenko wrote:
> Commit 7232398abc6a ("ARM: tegra: Convert PMC to a driver") changed tegra_resume()
> location storing from late to early and, as a result, broke suspend on Tegra20.
> PMC scratch register 41 is used by tegra LP1 resume code for retrieving stored
> physical memory address of common resume function and in the same time used by
> tegra20_cpu_shutdown() (shared by Tegra20 cpuidle driver and platform SMP code),
> which is storing CPU1 "resettable" status. It implies strict order of scratch
> register usage, otherwise resume function address is lost on Tegra20 after
> disabling non-boot CPU's on suspend. Fix it by storing "resettable" status in
> IRAM instead of PMC scratch register.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> Fixes: 7232398abc6a (ARM: tegra: Convert PMC to a driver)
> Cc: <stable@xxxxxxxxxxxxxxx> # v3.17+
> ---
> arch/arm/mach-tegra/cpuidle-tegra20.c | 5 ++---
> arch/arm/mach-tegra/reset-handler.S | 10 +++++++---
> arch/arm/mach-tegra/reset.h | 4 ++++
> arch/arm/mach-tegra/sleep-tegra20.S | 37 ++++++++++++++++++++---------------
> arch/arm/mach-tegra/sleep.h | 4 ++++
> 5 files changed, 38 insertions(+), 22 deletions(-)

I'm leaning towards applying this. Stephen, Alex, Peter: any objections?

Thierry

Attachment: pgpNoS7hpTd_l.pgp
Description: PGP signature