linux-kernel - Re: [PATCH 4/9] serial: sh-sci: Update the suspend/resume support

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: <2024110752-establish-subduing-225c@gregkh>
Date: Thu, 7 Nov 2024 09:49:05 +0100
From: Greg KH <gregkh@...uxfoundation.org>
To: Claudiu <claudiu.beznea@...on.dev>
Cc: geert+renesas@...der.be, magnus.damm@...il.com, robh@...nel.org,
	krzk+dt@...nel.org, conor+dt@...nel.org, mturquette@...libre.com,
	sboyd@...nel.org, jirislaby@...nel.org, p.zabel@...gutronix.de,
	lethal@...ux-sh.org, g.liakhovetski@....de,
	ysato@...rs.sourceforge.jp, ulrich.hecht+renesas@...il.com,
	linux-renesas-soc@...r.kernel.org, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
	linux-serial@...r.kernel.org,
	Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
Subject: Re: [PATCH 4/9] serial: sh-sci: Update the suspend/resume support

On Wed, Nov 06, 2024 at 02:01:13PM +0200, Claudiu wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
> 
> The Renesas RZ/G3S supports a power saving mode where power to most of the
> SoC components is turned off. When returning from this power saving mode,
> SoC components need to be re-configured.
> 
> The SCIFs on the Renesas RZ/G3S need to be re-configured as well when
> returning from this power saving mode. The sh-sci code already configures
> the SCIF clocks, power domain and registers by calling uart_resume_port()
> in sci_resume(). On suspend path the SCIF UART ports are suspended
> accordingly (by calling uart_suspend_port() in sci_suspend()). The only
> missing setting is the reset signal. For this assert/de-assert the reset
> signal on driver suspend/resume.
> 
> In case the no_console_suspend is specified by the user, the registers need
> to be saved on suspend path and restore on resume path. To do this the
> sci_console_setup() function was added. There is no need to cache/restore
> the status or FIFO registers. Only the control registers. To differentiate
> b/w these, the struct sci_port_params::regs was updated with a new member
> that specifies if the register needs to be chached on suspend. Only the
> RZ_SCIFA instances were updated with this new support as the hardware for
> the rest of variants was missing for testing.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@...renesas.com>
> ---
>  drivers/tty/serial/sh-sci.c | 53 ++++++++++++++++++++++++++++++-------
>  1 file changed, 44 insertions(+), 9 deletions(-)

Does not apply as I didn't take the atomic_t patch :(

thanks,

greg k-h