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 :-( -- balbi
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