On Wed, Jul 14, 2021 at 09:40:13AM +0300, Felipe Balbi wrote: > > Hi, > > Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes: > >> Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes: > >>> Wesley Cheng wrote: > >>>> Some devices have USB compositions which may require multiple endpoints > >>>> that support EP bursting. HW defined TX FIFO sizes may not always be > >>>> sufficient for these compositions. By utilizing flexible TX FIFO > >>>> allocation, this allows for endpoints to request the required FIFO depth to > >>>> achieve higher bandwidth. With some higher bMaxBurst configurations, using > >>>> a larger TX FIFO size results in better TX throughput. > >>>> > >>>> By introducing the check_config() callback, the resizing logic can fetch > >>>> the maximum number of endpoints used in the USB composition (can contain > >>>> multiple configurations), which helps ensure that the resizing logic can > >>>> fulfill the configuration(s), or return an error to the gadget layer > >>>> otherwise during bind time. > >>>> > >>>> Signed-off-by: Wesley Cheng <wcheng@xxxxxxxxxxxxxx> > >>>> --- > >>>> drivers/usb/dwc3/core.c | 15 +++ > >>>> drivers/usb/dwc3/core.h | 16 ++++ > >>>> drivers/usb/dwc3/ep0.c | 2 + > >>>> drivers/usb/dwc3/gadget.c | 232 ++++++++++++++++++++++++++++++++++++++++++++++ > >>>> 4 files changed, 265 insertions(+) > >>>> > >>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c > >>>> index ba74ad7..b194aecd 100644 > >>>> --- a/drivers/usb/dwc3/core.c > >>>> +++ b/drivers/usb/dwc3/core.c > >>>> @@ -1267,6 +1267,7 @@ static void dwc3_get_properties(struct dwc3 *dwc) > >>>> u8 rx_max_burst_prd; > >>>> u8 tx_thr_num_pkt_prd; > >>>> u8 tx_max_burst_prd; > >>>> + u8 tx_fifo_resize_max_num; > >>>> const char *usb_psy_name; > >>>> int ret; > >>>> > >>>> @@ -1282,6 +1283,13 @@ static void dwc3_get_properties(struct dwc3 *dwc) > >>>> */ > >>>> hird_threshold = 12; > >>>> > >>>> + /* > >>>> + * default to a TXFIFO size large enough to fit 6 max packets. This > >>>> + * allows for systems with larger bus latencies to have some headroom > >>>> + * for endpoints that have a large bMaxBurst value. > >>>> + */ > >>>> + tx_fifo_resize_max_num = 6; > >>>> + > >>>> dwc->maximum_speed = usb_get_maximum_speed(dev); > >>>> dwc->max_ssp_rate = usb_get_maximum_ssp_rate(dev); > >>>> dwc->dr_mode = usb_get_dr_mode(dev); > >>>> @@ -1325,6 +1333,11 @@ static void dwc3_get_properties(struct dwc3 *dwc) > >>>> &tx_thr_num_pkt_prd); > >>>> device_property_read_u8(dev, "snps,tx-max-burst-prd", > >>>> &tx_max_burst_prd); > >>>> + dwc->do_fifo_resize = device_property_read_bool(dev, > >>>> + "tx-fifo-resize"); > >>>> + if (dwc->do_fifo_resize) > >>>> + device_property_read_u8(dev, "tx-fifo-max-num", > >>>> + &tx_fifo_resize_max_num); > >>> > >>> Why is this check here? The dwc->tx_fifo_resize_max_num should store > >>> whatever property the user sets. Whether the driver wants to use this > >> > >> Ack! > >> > >>> property should depend on "dwc->do_fifo_resize". Also why don't we have > >>> "snps," prefix to be consistent with the other properties? > >> > >> Ack! > >> > >>> Can we enforce to a single property? If the designer wants to enable > >>> this feature, he/she can to provide the tx-fifo-max-num. This would > >>> simplify the driver a bit. Since this is to optimize for performance, > >>> the user should know/want/test the specific value if they want to set > >>> for their setup and not hoping that the default setting not break their > >>> setup. So we can remove the "do_fifo_resize" property and just check > >>> whether tx_fifo_resize_max_num is set. > >> > >> Ack! > >> > >> All very valid points :-) > >> > > > > Looks like this series already landed in Greg's testing branch. Not sure > > how we usually handle this to address some of our concerns. Add fix > > patches on top of Greg's testing branch? > > yup, no choice anymore :-( I took these as they seemed correct. If they need to be reverted, that's fine I can do that. But it looks like Wesley can just make some simple changes on top of them to resolve the remaining issues, right? thanks, greg k-h
