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=-16.4 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 7DA92C11F67 for ; Wed, 14 Jul 2021 06:51:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 57F086136E for ; Wed, 14 Jul 2021 06:51:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238179AbhGNGyk (ORCPT ); Wed, 14 Jul 2021 02:54:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:51446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238104AbhGNGyj (ORCPT ); Wed, 14 Jul 2021 02:54:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 827FF613B2; Wed, 14 Jul 2021 06:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626245507; bh=tWzM/nAg8eNclAWFOFTlsUjc9uWiLTSIVfdSSt10jL4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sRJOxyu/EdZaF04N9N1DlqaOt2cGHZmWOh4usfSdHsFkoquPVsjfvtUmOKIe0ftRU 775JYYR3exPV1xcDXxSR9ymA5hulGZ9TxN0O+fp1LCFXwo7z6TBJEDO4RorDneLvYv r/jacMiOvCX0K5NFYc4RqxwAAqJK/nhtVILg4FPM= Date: Wed, 14 Jul 2021 08:51:44 +0200 From: "gregkh@linuxfoundation.org" To: Thinh Nguyen Cc: Felipe Balbi , Wesley Cheng , "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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 14, 2021 at 03:10:25AM +0000, Thinh Nguyen wrote: > Felipe Balbi wrote: > > > > Hi, > > > > 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 :-) > > > > 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? Yes please send patches on top of this series. thanks, greg k-h