On Mon, 23 Jan 2017, John Youn wrote: > On 1/22/2017 5:29 PM, Bryan O'Donoghue wrote: > > - DWC_USB3_NUM indicates the number of Device mode single directional > > endpoints, including OUT and IN endpoint 0. > > > > - DWC_USB3_NUM_IN_EPS indicates the maximum number of Device mode IN > > endpoints active at any time, including control endpoint 0. > > > > It's possible to configure RTL such that DWC_USB3_NUM_EPS is equal to > > DWC_USB3_NUM_IN_EPS. > > > > dwc3-core calculates the number of OUT endpoints as DWC_USB3_NUM minus > > DWC_USB3_NUM_IN_EPS. If RTL has been configured with DWC_USB3_NUM_IN_EPS > > equal to DWC_USB3_NUM then dwc3-core will calculate the number of OUT > > endpoints as zero. > > > > For example a from dwc3_core_num_eps() shows: > > [ 1.565000] /usb0@f01d0000: found 8 IN and 0 OUT endpoints > > > > This patch works around this case by detecting when DWC_USB3_NUM_EPS is > > equal to DWC3_USB3_NUM_IN_EPS and over-rides the calculation of the number > > What if NUM_IN_EPS=7 and NUM_EPS=8? You will still have a problem. > > It's possible to fix this for the general case rather than for this > specific case. What is the reason for computing NUM_OUT_EPS in the first place? Isn't it true that any endpoint can be used as an OUT endpoint? So the real restrictions on a configuration are: number of IN endpoints <= NUM_IN_EPS, and number of IN endpoints + number of OUT endpoints <= NUM_EPS, where ep0 must be counted twice, as both an IN and an OUT endpoint. The value of NUM_OUT_EPS isn't used and shouldn't matter. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
