On Mon, Mar 6, 2023 at 8:52 AM Andrew Davis afd@ti.com wrote:
Although there is usually not such a limitation (and when there is it is often only because the driver forgot to change the super small default), it is still correct here to break scatterlist element into chunks of dma_max_mapping_size().
Hey Andrew! Thanks for sending this out!
So *why* is it "correct here to break scatterlist element into chunks of dma_max_mapping_size()." ?
This might cause some issues for users with misbehaving drivers. If bisecting has landed you on this commit, make sure your drivers both set dma_set_max_seg_size() and are checking for contiguousness correctly.
Why is this change worth the risk? (If this is really likely to break folks, should we maybe provide warnings initially instead? Maybe falling back to the old code if we can catch the failure?)
I don't really object to the change, just want to make sure the commit message is more clear on why we should make this change, what the benefit will be along with the potential downsides.
thanks -john