linux-kernel - Re: [PATCH v2 1/4] firmware: arm_scmi: Bypass setting fwnode for scmi cpufreq

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: <CAGETcx8MXpLntMu4=9qECdZJzJLJbWa8ziH8XcW=yJNDAgD=Vw@mail.gmail.com>
Date: Thu, 13 Feb 2025 00:17:06 -0800
From: Saravana Kannan <saravanak@...gle.com>
To: Cristian Marussi <cristian.marussi@....com>
Cc: Dan Carpenter <dan.carpenter@...aro.org>, Peng Fan <peng.fan@....nxp.com>, 
	Sudeep Holla <sudeep.holla@....com>, Linus Walleij <linus.walleij@...aro.org>, 
	Dong Aisheng <aisheng.dong@....com>, Fabio Estevam <festevam@...il.com>, 
	Shawn Guo <shawnguo@...nel.org>, Jacky Bai <ping.bai@....com>, 
	Pengutronix Kernel Team <kernel@...gutronix.de>, Sascha Hauer <s.hauer@...gutronix.de>, arm-scmi@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	linux-gpio@...r.kernel.org, imx@...ts.linux.dev, Peng Fan <peng.fan@....com>
Subject: Re: [PATCH v2 1/4] firmware: arm_scmi: Bypass setting fwnode for scmi cpufreq

On Thu, Feb 6, 2025 at 3:42 AM Cristian Marussi
<cristian.marussi@....com> wrote:
>
> On Thu, Feb 06, 2025 at 02:31:19PM +0300, Dan Carpenter wrote:
> > On Thu, Feb 06, 2025 at 06:52:20PM +0800, Peng Fan wrote:
> > > On Wed, Feb 05, 2025 at 03:45:00PM +0300, Dan Carpenter wrote:
> > > >On Mon, Jan 20, 2025 at 03:13:29PM +0800, Peng Fan (OSS) wrote:
> > > >> diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
> > > >> index 2c853c84b58f530898057e4ab274ba76070de05e..7850eb7710f499888d32aebf5d99df63db8bfa26 100644
> > > >> --- a/drivers/firmware/arm_scmi/bus.c
> > > >> +++ b/drivers/firmware/arm_scmi/bus.c
> > > >> @@ -344,6 +344,21 @@ static void __scmi_device_destroy(struct scmi_device *scmi_dev)
> > > >>          device_unregister(&scmi_dev->dev);
> > > >>  }
> > > >>
> > > >> +static int
> > > >> +__scmi_device_set_node(struct scmi_device *scmi_dev, struct device_node *np,
> > > >> +                       int protocol, const char *name)
> > > >> +{
> > > >> +        /* cpufreq device does not need to be supplier from devlink perspective */
> > > >> +        if ((protocol == SCMI_PROTOCOL_PERF) && !strcmp(name, "cpufreq")) {
> > > >
> > > >I don't love this...  It seems like an hack.  Could we put a flag
> > > >somewhere instead?  Perhaps in scmi_device?  (I'm just saying that
> > > >because that's what we're passing to this function).
> > >
> > > This means when creating scmi_device, a flag needs to be set which requires
> > > to extend scmi_device_id to include a flag entry or else.
> > >
> > > As below in scmi-cpufreq.c
> > > { SCMI_PROTOCOL_PERF, "cpufreq", SCMI_FWNODE_NO }
> > >
> >
> > Yeah, I like that.
> >
> > -     if ((protocol == SCMI_PROTOCOL_PERF) && !strcmp(name, "cpufreq")) {
> > +     if (scmi_dev->flags & SCMI_FWNODE_NO) {
> >
> > Or we could do something like "if (scmi_dev->no_fwnode) {"
>
> I proposed a flag a few review ago about this, it shoule come somehow
> from the device_table above like Peng was proposing, so that a driver
> can just declare that does NOT need fw_devlink.

Sorry, looks I replied to v1 series. Can you take a look at that
response please?
https://lore.kernel.org/lkml/CAGETcx87Stfkru9gJrc1sf=PtFGLY7=jrfFaCzK5Z4hq+2TCzg@mail.gmail.com/

If that suggestion I gave there would work, then that's the cleanest
approach. This patch series is just kicking the can down the road (or
down an inch).

-Saravana