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Message-ID: <14d7ed85-7ab6-04d9-1958-d5ceae2a79f8@collabora.com>
Date:   Mon, 1 May 2023 18:42:40 +0300
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Subject: Re: [PATCH v2 6/7] dma-buf: Change locking policy for mmap()
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From:   Dmitry Osipenko <dmitry.osipenko@collabora.com>
To:     =?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, linux-arm-msm@vger.kernel.org,
        kernel@collabora.com, Sumit Semwal <sumit.semwal@linaro.org>,
        Benjamin Gaignard <benjamin.gaignard@collabora.com>,
        Liam Mark <lmark@codeaurora.org>,
        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>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        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>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Amol Maheshwari <amahesh@qti.qualcomm.com>,
        Emil Velikov <emil.l.velikov@gmail.com>
References: <20230406160637.541702-1-dmitry.osipenko@collabora.com>
 <20230406160637.541702-7-dmitry.osipenko@collabora.com>
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On 4/6/23 19:06, 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, may I add yours ack to this patch?

-- 
Best regards,
Dmitry