On Sun, Jun 27, 2021 at 12:18:14AM +0300, Igor Kononenko wrote: > SCSI command handlers currently have an ambiguous return value. This (I dislike very much this way of writing patch descriptions. Unless the reader has already looked at the email subject line and remembers that this patch affects the mass-storage gadget, he will think the sentence above is talking about command handlers in the SCSI core -- a completely different part of the kernel. When writing patch descriptions, please do not assume that the reader already knows what the patch is about.) > return value may indicate the length of the data written to the response > buffer and the command's processing status. Thus, the understanding of > command handling may be implicit. The return value is _not_ ambiguous. If the value is >= 0 then it is a data length, otherwise it is a status. Yes, this is implicit, but it is a very common pattern used throughout the kernel and everyone understands it. > After this patch, the output buffer's size will be set in the > 'data_size_to_handle' field of 'struct fsg_common', and the command > handler's return value indicates only the processing status. What is the reason for making this change? Does it fix any problems or prepare the way for any future patches? It seems like this is completely unnecessary. Alan Stern > Tested: By probing the USBGadget Mass-Storage on the YADRO VEGMAN > BMC(AST2500) sample, each SCSI command was sent through HOST->BMC; the > USBGadget MassStorage debug print showed all sent commands works > properly. > > Signed-off-by: Igor Kononenko <i.kononenko@xxxxxxxxx>
