Hi Magnus,
On Fri, Sep 30, 2016 at 9:04 AM, Magnus Damm <magnus.damm@xxxxxxxxx> wrote:
> On Tue, Sep 27, 2016 at 9:37 PM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
>> On Mon, Aug 22, 2016 at 4:44 PM, Geert Uytterhoeven
>> <geert+renesas@xxxxxxxxx> wrote:
>>> This patch series is an attempt to allow booting secondary CPU cores on
>>> R-Car Gen2 when hardware debug mode is enabled. In this mode, reset
>>> requests derived from power-shutoff to the AP-system CPU cores must be
>>> enabled before the AP-system cores first resume from power-shutoff. Else
>>> resume may fail, causing the system to hang during boot. Currently we
>>> avoid the hang by prohibiting booting secondary CPU cores when hardware
>>> debug mode is enabled.
>>>
>>> On all R-Car Gen2 SoCs, hardware debug mode is enabled by setting
>>> MD21=1. On both Koelsch and Lager, this is done by setting mode switch
>>> SW8-4 to OFF.
>>>
>>> Unfortunately the hang is not easy to reproduce: I only saw it (on
>>> Koelsch) during real cold boot (power off during the night), and even
>>> then it's not guaranteed to trigger. Pressing the reset button
>>> afterwards recovers the system, and a subsequent boot will succeed
>>> (incl. secondary CPU core boot).
>>>
>>> This series configures the reset requests as documented in the R-Car
>>> Gen2 datasheet, and removes the check for MD21 during secondary CPU
>>> bringup. It was inspired by CPU-specific patches in the BSP by
>>> Nakamura-san.
>>>
>>> This series has been boot-tested on r8a7791/koelsch (both debug mode and
>>> normal mode), on r8a7790/lager and r8a7793/gose (normal mode only), and
>>> on r8a7794/alt (normal mode UP only).
>>
>> Any comments?
>> Any objection to applying this series?
>>
>> I've been running my Koelsch with MD21=1 since I posted this series,
>> and it has been included in renesas-drivers since the beginning of September.
>>
>> My main motivation to push this is that it removes two more users of
>> rcar_gen2_read_mode_pins(). After this, the only remaining user is the
>> clock driver, invoked from rcar_gen2_timer_init().
>
> I have no objections, but I'm curious if the series received enough
> testing (with debug mode enabled) on earlier R-Car Gen2 platforms like
> r8a7790/lager?
Let's see what Hiep has to say, who tests Lager with both debug mode
enabled and disabled...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
