From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBEBCC636C8 for ; Tue, 20 Jul 2021 11:46:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AD6F16113C for ; Tue, 20 Jul 2021 11:46:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237978AbhGTLE6 (ORCPT ); Tue, 20 Jul 2021 07:04:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:46686 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237255AbhGTLB7 (ORCPT ); Tue, 20 Jul 2021 07:01:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7D52C61029; Tue, 20 Jul 2021 11:41:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626781283; bh=PG0tu/4uqGOvHH15ANqr2Muvuf7Y5q6HFJHr/FyecDs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Zscox8jNph++6sZDK4wA5sYW6EGSRVtVL+LSZ2d753xAmHd2qQI9uIWkhRBs+kRwR nOX5NWibEBaal6O5c0krrwez4RUai6ENwBI6mnLoqteSd6JCKsUSs5rx8YiSwtAPYy fXNPygPlphRy5W3Tma6OlXurRqBnOnQAxFItmtNQ= Date: Tue, 20 Jul 2021 13:41:20 +0200 From: "gregkh@linuxfoundation.org" To: Wesley Cheng Cc: Felipe Balbi , Thinh Nguyen , "agross@kernel.org" , "bjorn.andersson@linaro.org" , "robh+dt@kernel.org" , "frowand.list@gmail.com" , "linux-usb@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , "devicetree@vger.kernel.org" , "jackp@codeaurora.org" Subject: Re: [PATCH v14 3/6] usb: dwc3: Resize TX FIFOs to meet EP bursting requirements Message-ID: References: <1625908395-5498-1-git-send-email-wcheng@codeaurora.org> <1625908395-5498-4-git-send-email-wcheng@codeaurora.org> <87czrmzjym.fsf@kernel.org> <877dhtz9de.fsf@kernel.org> <6bc35b95-8386-1a6b-46dd-f33035e6dee5@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6bc35b95-8386-1a6b-46dd-f33035e6dee5@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 14, 2021 at 12:30:07AM -0700, Wesley Cheng wrote: > > > On 7/13/2021 11:40 PM, Felipe Balbi wrote: > > > > Hi, > > > > Thinh Nguyen writes: > >>> Thinh Nguyen 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 > >>>>> --- > >>>>> 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. Any hint as to when these fixups will be sent? thanks, greg k-h