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Message-ID: <91466907-d4e1-1619-27a8-a49a01cbc8f1@collabora.com>
Date:   Wed, 31 May 2023 22:58:19 +0300
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Subject: Re: [PATCH v4 5/6] dma-buf: Change locking policy for mmap()
From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
To:     Sumit Semwal <sumit.semwal@linaro.org>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
Cc:     linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org,
        linux-tegra@vger.kernel.org, kernel@collabora.com,
        Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        Brian Starkey <Brian.Starkey@arm.com>,
        John Stultz <jstultz@google.com>,
        Gerd Hoffmann <kraxel@redhat.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Tomi Valkeinen <tomba@kernel.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Tomasz Figa <tfiga@chromium.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Emil Velikov <emil.l.velikov@gmail.com>
References: <20230529223935.2672495-1-dmitry.osipenko@collabora.com>
 <20230529223935.2672495-6-dmitry.osipenko@collabora.com>
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On 5/30/23 01:39, Dmitry Osipenko wrote:
> Change locking policy of mmap() callback, making exporters responsible
> for handling dma-buf reservation locking. Previous locking policy stated
> that dma-buf is locked for both importers and exporters by the dma-buf
> core, which caused a deadlock problem for DRM drivers in a case of
> self-imported dma-bufs which required to take the lock from the DRM
> exporter side.
> 
> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>  drivers/dma-buf/dma-buf.c | 17 +++--------------
>  1 file changed, 3 insertions(+), 14 deletions(-)

Christian, you acked the drm patch of this series sometime ago, perhaps
it also implies implicit ack to this patch, but I'd prefer to have the
explicit ack. I'll apply this series to drm-misc later this week if
you'll approve this dma-buf change. Thanks in advance!

-- 
Best regards,
Dmitry