On 7/13/2021 11:40 PM, 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 :-) >>> Hi Thinh/Felipe, >> >> 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 :-( > Let me review your feedback, which had some good points. We can add a change addressing everything on top of what is merged on Greg's branch. Thanks for all the input! Thanks Wesley Cheng -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
