Hi, On 2024/2/27 18:14, Thomas Zimmermann wrote:
Acquire the buffer object's reservation lock in drm_gem_pin() and remove locking the drivers' GEM callbacks where necessary. Same for unpin(). DRM drivers and memory managers modified by this patch will now have correct dma-buf locking semantics: the caller is responsible for holding the reservation lock when calling the pin or unpin callback. DRM drivers and memory managers that are not modified will now be protected against concurent invocation of their pin and unpin callbacks.
'concurent' -> 'concurrent'
PRIME does not implement struct dma_buf_ops.pin, which requires the caller to hold the reservation lock. It does implement struct dma_buf_ops.attach, which requires to callee to acquire the reservation lock.
which requires 'the' callee to acquire the reservation lock.
The PRIME code uses drm_gem_pin(), so locks are now taken as specified. Same for unpin and detach. The patch harmonizes GEM pin and unpin to have non-interruptible reservation locking across all drivers, as is already the case for vmap and vunmap. This affects gem-shmem, gem-vram, loongson, qxl and radeon. Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reviewed-by: Zack Rusin <zack.rusin@xxxxxxxxxxxx>
Tested with drm/loongson, play with a few days. Switch to virtual terminal, then switch back is fine. not found problems yet. So, Tested-by: Sui Jingfeng <sui.jingfeng@xxxxxxxxx>