linux-kernel - Re: [RFT PATCH v2] serial: core: Call device_set_awake

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAMuHMdX_uojDmx3pH--KsBcae=1VmcNupedGBwovVQcU+z14sg@mail.gmail.com>
Date: Thu, 25 Apr 2024 09:48:39 +0200
From: Geert Uytterhoeven <geert@...ux-m68k.org>
To: Claudiu <claudiu.beznea@...on.dev>
Cc: gregkh@...uxfoundation.org, jirislaby@...nel.org, tony@...mide.com, 
	andriy.shevchenko@...ux.intel.com, l.sanfilippo@...bus.com, 
	tglx@...utronix.de, geert+renesas@...der.be, ulf.hansson@...aro.org, 
	peng.fan@....com, linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org, 
	linux-pm@...r.kernel.org, Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
Subject: Re: [RFT PATCH v2] serial: core: Call device_set_awake_path() for
 console port

On Thu, Apr 25, 2024 at 9:09 AM Claudiu <claudiu.beznea@...on.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
>
> In case the UART port is used as a console, no_console_suspend is
> available in bootargs and UART port is part of a software-controlled power
> domain we need to call device_set_awake_path(). This lets the power
> domain core code know that this domain should not be powered off
> during system suspend. Otherwise, the UART port power domain is turned off,
> nothing is printed while suspending and the suspend/resume process is
> blocked. This was detected on the Renesas RZ/G3S SoC while adding support
> for power domains.
>
> Based on code investigation, this issue is present on other SoCs (e.g.,
> Renesas R-Mobile A1 [1], IMX8QXP [2]) and different SoCs have particular
> implementation to handle it. Due to this the patch added the call of
> device_set_awake_path() in uart_suspend_port() instead of having it in
> the platform specific UART driver.
>
> [1] https://elixir.bootlin.com/linux/v6.9-rc5/source/drivers/pmdomain/renesas/rmobile-sysc.c#L116
> [2] https://elixir.bootlin.com/linux/v6.9-rc5/source/drivers/pmdomain/imx/scu-pd.c#L357
>
> Suggested-by: Ulf Hansson <ulf.hansson@...aro.org>
> Suggested-by: Geert Uytterhoeven <geert@...ux-m68k.org>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@...der.be>

Works fine on R-Mobile APE6 with console suspend support removed from
rmobile-sysc.c
Tested-by: Geert Uytterhoeven <geert+renesas@...der.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68korg

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