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Am 15.04.25 um 15:10 schrieb Simona Vetter:<br>
<blockquote type="cite" cite="mid:Z_5a3ckZiY-fINNW@phenom.ffwll.local"><span style="white-space: pre-wrap">
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<pre class="moz-quote-pre" wrap="">This is for devices who only want to do a vmap of the buffer, isn't it?
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... it's for the vmap only case, where you might not even have a struct
device. Or definitely not a reasonable one, like maybe a faux_bus device
or some device on a bus that really doesn't do dma (e.g. spi or i2c), and
where hence dma_buf_map_attachment is just something you never ever want
to do.</pre>
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Even in that case I would still suggest to at least create an
attachment to let the exporter know that somebody is doing something
with it's buffer.<br>
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That is also important for move notification since you can't do
those without an attachment.<br>
<br>
BTW: What is keeping a vmap alive after dropping the reservation
lock? There is no pinning whatsoever as far as I can see.<br>
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<blockquote type="cite" cite="mid:Z_5a3ckZiY-fINNW@phenom.ffwll.local">
<pre class="moz-quote-pre" wrap="">I think we might want to transform obj->import_attach into a union or
tagged pointer or something like that, which can cover both cases. And
maybe a drm_gem_bo_imported_dma_buf() helper that gives you the dma_buf no
matter what if it's imported, or NULL if it's allocated on that
drm_device?</pre>
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Yeah, I had the same idea before as well. Just didn't know if that
was something worth looking into.<br>
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Regards,<br>
Christian.<br>
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Cheers, Sima
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