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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 47FB9C11F67 for ; Wed, 14 Jul 2021 06:40:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2F01561360 for ; Wed, 14 Jul 2021 06:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238135AbhGNGnO (ORCPT ); Wed, 14 Jul 2021 02:43:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:49950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238064AbhGNGnO (ORCPT ); Wed, 14 Jul 2021 02:43:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5F6B0613A9; Wed, 14 Jul 2021 06:40:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626244823; bh=9Bx9vBoPD5uzTtwmzVBrNtfVfkmNpr6c8EkbHx7wB8Q=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=kIKPUGLlKcRUN1II5SBUxh38k+ZGdOTusaV0paftR8s1uYZ2op1Hot+Vk7n1TURTp aFG0BnZEWTNQYNKrnnWU/0pEfZmdGS+9d4pyFY4OKEEb3swU9+zDtr4dVaAYu4Xn2Y InSTQloEN5hRZOI6owkajV9lHdnCwhpFVQB+1JhclAXsZp5mM0+QJenpAax/5JXx3/ SWf/9lEgbH8Gya9bWfm2iSBZiU3pqyYFKW9tmLn+zORR5p42MnqoeC+B1q0Etb+PV6 qgC+jXdZ7MDOyiN385SHIEyBlJZyirosl04EXJUg6punvT7Eme6PPDsQoJFxWKDpKz AaTUt6/W2Pvew== From: Felipe Balbi To: Thinh Nguyen , Thinh Nguyen , Wesley Cheng , "gregkh@linuxfoundation.org" , "agross@kernel.org" , "bjorn.andersson@linaro.org" , "robh+dt@kernel.org" , "frowand.list@gmail.com" Cc: "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 In-Reply-To: References: <1625908395-5498-1-git-send-email-wcheng@codeaurora.org> <1625908395-5498-4-git-send-email-wcheng@codeaurora.org> <87czrmzjym.fsf@kernel.org> Date: Wed, 14 Jul 2021 09:40:13 +0300 Message-ID: <877dhtz9de.fsf@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable 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 dep= th 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 fet= ch >>>> the maximum number of endpoints used in the USB composition (can conta= in >>>> multiple configurations), which helps ensure that the resizing logic c= an >>>> 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; >>>>=20=20 >>>> @@ -1282,6 +1283,13 @@ static void dwc3_get_properties(struct dwc3 *dw= c) >>>> */ >>>> hird_threshold =3D 12; >>>>=20=20 >>>> + /* >>>> + * 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 =3D 6; >>>> + >>>> dwc->maximum_speed =3D usb_get_maximum_speed(dev); >>>> dwc->max_ssp_rate =3D usb_get_maximum_ssp_rate(dev); >>>> dwc->dr_mode =3D usb_get_dr_mode(dev); >>>> @@ -1325,6 +1333,11 @@ static void dwc3_get_properties(struct dwc3 *dw= c) >>>> &tx_thr_num_pkt_prd); >>>> device_property_read_u8(dev, "snps,tx-max-burst-prd", >>>> &tx_max_burst_prd); >>>> + dwc->do_fifo_resize =3D 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 >>=20 >> Ack! >>=20 >>> property should depend on "dwc->do_fifo_resize". Also why don't we have >>> "snps," prefix to be consistent with the other properties? >>=20 >> Ack! >>=20 >>> 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. >>=20 >> Ack! >>=20 >> All very valid points :-) >>=20 > > 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 :-( =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQFFBAEBCAAvFiEE9DumQ60WEZ09LIErzlfNM9wDzUgFAmDuhs0RHGJhbGJpQGtl cm5lbC5vcmcACgkQzlfNM9wDzUiNVAf/fSuK7IebP/n3bns0cJxXRsVVVcVHZJV5 Wmp9xn9vGwECNnDPHurSubeBDTK22ZTY95xMIPrma99CjfLBJ3VBTwSA5AzUr1sA OBcYuUG5tpx/eGPvKYDUnjBEvP86QBbKa10iMgufBgMtiSl4s58sI5XFQ3NqWLnx JEVK2ExtjCrCGZUM+qW/yjKXsP486hxiRcXWhYrE9jeP+q1d+4c9EaelKn2a5EVS Jook+e3iwv6jYQHOxcLXGLegjjaXn9qLMDNYBC5E7ZyoT/fJJPzz6OO1qLWqjSV/ 8XP/6+y5QF3HTe2ByGgvyU4nGbtt5nLN9bHBazJP2r5SC+q8Hp+ovA== =ayGw -----END PGP SIGNATURE----- --=-=-=--