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Message-ID: <d348a2dc080d24d43d55128223be6e4a88c73053.camel@kernel.org>
Subject: Re: [PATCH 3/5] drm/vc4: hdmi: Set a default HSM rate
From:   nicolas saenz julienne <nsaenz@kernel.org>
To:     Maxime Ripard <maxime@cerno.tech>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Daniel Vetter <daniel.vetter@intel.com>,
        David Airlie <airlied@linux.ie>
Cc:     linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org,
        linux-rpi-kernel@lists.infradead.org,
        Mike Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Michael Stapelberg <michael@stapelberg.ch>,
        Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 30 Sep 2021 17:51:45 +0200
In-Reply-To: <20210922125419.4125779-4-maxime@cerno.tech>
References: <20210922125419.4125779-1-maxime@cerno.tech>
         <20210922125419.4125779-4-maxime@cerno.tech>
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On Wed, 2021-09-22 at 14:54 +0200, Maxime Ripard wrote:
> When the firmware doesn't setup the HSM rate (such as when booting
> without an HDMI cable plugged in), its rate is 0 and thus any register
> access results in a CPU stall, even though HSM is enabled.
> 
> Let's enforce a minimum rate at boot to avoid this issue.
> 
> Fixes: 4f6e3d66ac52 ("drm/vc4: Add runtime PM support to the HDMI encoder driver")
> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> ---

Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Tested-by: Nicolas Saenz Julienne <nsaenz@kernel.org>

Regards,
Nicolas