linux-kernel - Re: [PATCH v4 5/7] drm/vc4: hdmi: Rework hdmi_enable

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] [day] [month] [year] [list]

Date:   Wed, 26 Oct 2022 18:14:00 +0200
From:   maxime@...no.tech
To:     Dave Stevenson <dave.stevenson@...pberrypi.com>
Cc:     Daniel Vetter <daniel@...ll.ch>, Emma Anholt <emma@...olt.net>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Ray Jui <rjui@...adcom.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        David Airlie <airlied@...ux.ie>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@...adcom.com>,
        Scott Branden <sbranden@...adcom.com>,
        Stefan Wahren <stefan.wahren@...e.com>,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        Dom Cobley <popcornmix@...il.com>, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-rpi-kernel@...ts.infradead.org
Subject: Re: [PATCH v4 5/7] drm/vc4: hdmi: Rework hdmi_enable_4kp60 detection
 code

Hi Dave,

On Wed, Oct 26, 2022 at 05:00:25PM +0100, Dave Stevenson wrote:
> > +
> > +               node = rpi_firmware_find_node();
> > +               if (!node)
> > +                       return -EINVAL;
> > +
> > +               firmware = rpi_firmware_get(node);
> > +               of_node_put(node);
> > +               if (!firmware)
> > +                       return -EPROBE_DEFER;
> > +
> >                 hvs->core_clk = devm_clk_get(&pdev->dev, NULL);
> >                 if (IS_ERR(hvs->core_clk)) {
> >                         dev_err(&pdev->dev, "Couldn't get core clock\n");
> >                         return PTR_ERR(hvs->core_clk);
> >                 }
> >
> > +               max_rate = rpi_firmware_clk_get_max_rate(firmware,
> > +                                                        RPI_FIRMWARE_CORE_CLK_ID);
> > +               rpi_firmware_put(firmware);
> > +               if (max_rate >= 550000000)
> > +                       hvs->vc5_hdmi_enable_scrambling = true;
> > +
> > +               hvs->max_core_rate = max_rate;
> 
> I was going to query the reason for storing this value, but it's used
> when we get to patch 7/7.
> I won't quibble about having it as an unused value for 2 patches.

Yeah, it felt natural to do it in that patch, even though it's indeed
only useful in a couple of patches.

Maxime