linux-kernel - Re: [PATCH v4 6/6] drm/shmem-helper: Switch to reservation lock

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Message-ID: <4f652b3b-8691-84f4-037a-64950a30d496@collabora.com>
Date:   Mon, 26 Jun 2023 16:05:33 +0300
From:   Dmitry Osipenko <dmitry.osipenko@...labora.com>
To:     Boris Brezillon <boris.brezillon@...labora.com>
Cc:     Sumit Semwal <sumit.semwal@...aro.org>,
        Christian König <christian.koenig@....com>,
        Benjamin Gaignard <benjamin.gaignard@...labora.com>,
        Brian Starkey <Brian.Starkey@....com>,
        John Stultz <jstultz@...gle.com>,
        Gerd Hoffmann <kraxel@...hat.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Arnd Bergmann <arnd@...db.de>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Tomi Valkeinen <tomba@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Tomasz Figa <tfiga@...omium.org>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Emil Velikov <emil.l.velikov@...il.com>,
        intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        dri-devel@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
        kernel@...labora.com, linux-media@...r.kernel.org
Subject: Re: [PATCH v4 6/6] drm/shmem-helper: Switch to reservation lock

On 6/26/23 12:40, Boris Brezillon wrote:
> I think here is the major problem I have with this patch: you've made
> drm_gem_shmem_{get_pages,pin}() private, which forces me to call
> drm_gem_shmem_pin() in a path where I already acquired the resv lock
> (using the drm_exec infra proposed by Christian). That would
> probably work if you were letting ret == -EALREADY go through, but I'm
> wondering if it wouldn't be preferable to expose
> drm_gem_shmem_pin_locked().

You should be free to expose the necessary functions. They are private
because nobody need them so far and we don't want to export unused
functions.

-- 
Best regards,
Dmitry