diff options
Diffstat (limited to 'include/linux/dma-fence.h')
| -rw-r--r-- | include/linux/dma-fence.h | 32 |
1 files changed, 13 insertions, 19 deletions
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index eb9b05aa5aea..02dba8cd033d 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -166,7 +166,8 @@ struct dma_fence_ops { * released when the fence is signalled (through e.g. the interrupt * handler). * - * This callback is mandatory. + * This callback is optional. If this callback is not present, then the + * driver must always have signaling enabled. */ bool (*enable_signaling)(struct dma_fence *fence); @@ -190,11 +191,14 @@ struct dma_fence_ops { /** * @wait: * - * Custom wait implementation, or dma_fence_default_wait. + * Custom wait implementation, defaults to dma_fence_default_wait() if + * not set. * - * Must not be NULL, set to dma_fence_default_wait for default implementation. - * the dma_fence_default_wait implementation should work for any fence, as long - * as enable_signaling works correctly. + * The dma_fence_default_wait implementation should work for any fence, as long + * as @enable_signaling works correctly. This hook allows drivers to + * have an optimized version for the case where a process context is + * already available, e.g. if @enable_signaling for the general case + * needs to set up a worker thread. * * Must return -ERESTARTSYS if the wait is intr = true and the wait was * interrupted, and remaining jiffies if fence has signaled, or 0 if wait @@ -202,7 +206,7 @@ struct dma_fence_ops { * which should be treated as if the fence is signaled. For example a hardware * lockup could be reported like that. * - * This callback is mandatory. + * This callback is optional. */ signed long (*wait)(struct dma_fence *fence, bool intr, signed long timeout); @@ -218,17 +222,6 @@ struct dma_fence_ops { void (*release)(struct dma_fence *fence); /** - * @fill_driver_data: - * - * Callback to fill in free-form debug info. - * - * Returns amount of bytes filled, or negative error on failure. - * - * This callback is optional. - */ - int (*fill_driver_data)(struct dma_fence *fence, void *data, int size); - - /** * @fence_value_str: * * Callback to fill in free-form debug info specific to this fence, like @@ -242,8 +235,9 @@ struct dma_fence_ops { * @timeline_value_str: * * Fills in the current value of the timeline as a string, like the - * sequence number. This should match what @fill_driver_data prints for - * the most recently signalled fence (assuming no delayed signalling). + * sequence number. Note that the specific fence passed to this function + * should not matter, drivers should only use it to look up the + * corresponding timeline structures. */ void (*timeline_value_str)(struct dma_fence *fence, char *str, int size); |