On Sun, Aug 22, 2021 at 03:21:30PM +0200, Fabio M. De Francesco wrote: > On Sunday, August 22, 2021 2:39:34 PM CEST Greg KH wrote: > > On Sun, Aug 22, 2021 at 03:10:56PM +0300, Pavel Skripkin wrote: > > > On 8/22/21 1:59 PM, Fabio M. De Francesco wrote: > > > > On Sunday, August 22, 2021 12:09:29 PM CEST Pavel Skripkin wrote: > [...] > > > > So, it's up to the callers to test if (!_rtw_read*()) and then act > > > > accordingly. If they get 0 they should know how to handle the errors. > > > > > > Yes, but _rtw_read*() == 0 indicates 2 states: > > > 1. Error on transfer side > > > 2. Actual register value is 0 > > > > That's not a good design, it should be fixed. Note there is the new > > usb_control_msg_recv() function which should probably be used instead > > here, to prevent this problem from happening. > > I think that no functions should return 0 for signaling FAILURE. If I'm not > wrong, the kernel quite always prefers to return 0 on SUCCESS and <0 on > FAILURE. Why don't you just fix this? Fix what specifically here? The usb_control_msg() call? If so, that is why usb_control_msg_recv() was created, as sometimes you do want to do what usb_control_msg() does today (see the users in the USB core today for examples of why this is needed.) In general, yes, 0 is success, negative is error, and positive is the number of bytes read/written. Anyway, let's see the second round of patches here before continuing this thread... thanks, greg k-h
