On Fri, 2021-03-05 at 16:47 +0100, Greg Kroah-Hartman wrote: > On Fri, Mar 05, 2021 at 10:33:12AM -0500, Alan Stern wrote: > > On Fri, Mar 05, 2021 at 05:02:54PM +0800, Chunfeng Yun wrote: > > > Add a new function to convert bInterval into the time expressed > > > in 1us unit. > > > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> > > > --- > > > > > --- a/drivers/usb/common/common.c > > > +++ b/drivers/usb/common/common.c > > > @@ -165,6 +165,39 @@ enum usb_dr_mode usb_get_dr_mode(struct device *dev) > > > } > > > EXPORT_SYMBOL_GPL(usb_get_dr_mode); > > > > > > +unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd, > > > + enum usb_device_speed speed) > > > +{ > > > + unsigned int interval = 0; > > > + > > > + switch (usb_endpoint_type(epd)) { > > > + case USB_ENDPOINT_XFER_CONTROL: > > > + /* uframes per NAK */ > > > + if (speed == USB_SPEED_HIGH) > > > + interval = epd->bInterval; > > > + break; > > > + case USB_ENDPOINT_XFER_ISOC: > > > + interval = 1 << (epd->bInterval - 1); > > > + break; > > > + case USB_ENDPOINT_XFER_BULK: > > > + /* uframes per NAK */ > > > + if (speed == USB_SPEED_HIGH && usb_endpoint_dir_out(epd)) > > > + interval = epd->bInterval; > > > + break; > > > + case USB_ENDPOINT_XFER_INT: > > > + if (speed >= USB_SPEED_HIGH) > > > + interval = 1 << (epd->bInterval - 1); > > > + else > > > + interval = epd->bInterval; > > > + break; > > > + } > > > + > > > + interval *= (speed >= USB_SPEED_HIGH) ? 125 : 1000; > > > + > > > + return interval; > > > +} > > > +EXPORT_SYMBOL_GPL(usb_decode_interval); > > > > > --- a/include/linux/usb/ch9.h > > > +++ b/include/linux/usb/ch9.h > > > @@ -90,6 +90,17 @@ extern enum usb_ssp_rate usb_get_maximum_ssp_rate(struct device *dev); > > > */ > > > extern const char *usb_state_string(enum usb_device_state state); > > > > > > +/** > > > + * usb_decode_interval - Decode bInterval into the time expressed in 1us unit > > > + * @epd: The descriptor of the endpoint > > > + * @speed: The speed that the endpoint works as > > > + * > > > + * Function returns the interval expressed in 1us unit for servicing > > > + * endpoint for data transfers. > > > + */ > > > +unsigned int usb_decode_interval(const struct usb_endpoint_descriptor *epd, > > > + enum usb_device_speed speed); > > > > As a general rule, I believe people expect to find the kerneldoc for a > > function next to the function's definition, not next to the declaration > > in a header file. > > I was going to make the same review comment, but if you look above this > in that file, there's other kernel doc information in the .h file, so > this does match with the style of the file :( > > We can fix that all up later. I'll prepare a patch Thank you > > thanks, > > greg k-h