From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32CF2823BC; Tue, 23 Jan 2024 18:42:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706035353; cv=none; b=UcW17QE3e4b0YTpj/rFzozsLa/taHMsmz635zN2JIKxklu1Tm2K80kCe+S57uzj45Pbq2mU/jlc8hVtu8/YgP1TORrZ2IM/ZdJ0JXHRYYdgDU7glCqGfrH3hvjh1PSUd7kZ4jsWETV7I5Or1XbRXk8lFbCu2OQlJfL8bipntkH0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706035353; c=relaxed/simple; bh=L5CiyhJ7VmjD8jqZZfrKBqOIr3FlCEqBLQ1Y4nvSv68=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GNqlk3FRi3/UtTaGrCsKRUWX3FPxRNl2EtitgI9ONcXL4l+kPkhjV73jAShLAGLeJPY/u6oeRcIXOG5GvSCuVJXBrE3c3EvLJGhAcReIcei4ktTBfozbhGck69GFajJ6rcQZrZP1QL3D4o+nx9L/94l2jX8AD3OI91qYXjd7tQ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QgzdAMJf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QgzdAMJf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87EC4C433F1; Tue, 23 Jan 2024 18:42:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706035352; bh=L5CiyhJ7VmjD8jqZZfrKBqOIr3FlCEqBLQ1Y4nvSv68=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QgzdAMJfpJGkJP1P9EMq4+0ZzDYohgQmMHPDjUvtqtXyx5DMV15NtBUl0PnG1XST9 beJUdItmGbSaGAIfuZG2DyrcA8oukAqMR7wItzJ3+ut+2T4cV7PJXhKK3ItVmSYw7f l5nrwQ5CJ64qBT8arwFKilK9Q4E2zkIvTRjRXCgUIh1i9YHKA60Z6IHTgVPOolfIUa gV0QJ/uxDzFuz/6byKUvH7hH9BD18SrRJtyaERw9At4bbXpPEkoVerXMD1Ny5/2pmk kzdc153g6ZoydVJyXhi2HUbk5LgyBYuhb0ElD4/fKbP84+7bP3XKPGuOkvAUI7fhrg NTUHIMlpHqwCg== Date: Tue, 23 Jan 2024 18:42:27 +0000 From: Conor Dooley To: Frank Li Cc: thinh.nguyen@synopsys.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, balbi@kernel.org, devicetree@vger.kernel.org, gregkh@linuxfoundation.org, imx@lists.linux.dev, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, mark.rutland@arm.com, mathias.nyman@intel.com, pku.leo@gmail.com, sergei.shtylyov@cogentembedded.com Subject: Re: [PATCH 1/2] dt-bindings: usb: dwc3: Add system bus request info Message-ID: <20240123-nanometer-atlantic-6465b270043a@spud> References: <20240123170206.3702413-1-Frank.Li@nxp.com> <20240123-poking-geography-33be2b5ae578@spud> <20240123-anew-lilly-0d645bdbfb30@spud> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="gjo83bA3bLxaSiQd" Content-Disposition: inline In-Reply-To: --gjo83bA3bLxaSiQd Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jan 23, 2024 at 01:02:21PM -0500, Frank Li wrote: > On Tue, Jan 23, 2024 at 05:51:48PM +0000, Conor Dooley wrote: > > On Tue, Jan 23, 2024 at 12:49:27PM -0500, Frank Li wrote: > > > On Tue, Jan 23, 2024 at 05:27:13PM +0000, Conor Dooley wrote: > > > > On Tue, Jan 23, 2024 at 12:02:05PM -0500, Frank Li wrote: > > > > > Add device tree binding allow platform overwrite default value of= *REQIN in > > > > > GSBUSCFG0. > > > >=20 > > > > Why might a platform actually want to do this? Why does this need t= o be > > > > set at the board level and being aware of which SoC is in use is not > > > > sufficient for the driver to set the correct values? > > >=20 > > > In snps,dwc3.yaml, there are already similary proptery, such as > > > snps,incr-burst-type-adjustment. Use this method can keep whole dwc3 = usb > > > driver keep consistent. And not all platform try enable hardware > > > dma_cohenrence. It is configable for difference platform. > >=20 > > When you say "platform", what do you mean? I understand that term to > > mean a combination of board, soc and firmware. >=20 > In my company's environment, "platform" is "board". I will use "board" in > future. Is it big difference here? Nah, that's close enough that it makes no difference here. I'd still like an explanation for why a platform would need to actually set these properties though, and why information about coherency cannot be determined from whether or not the boss the usb controller is on is communicated to be dma coherent via the existing devicetree properties for that purpose. Thanks, Conor. > > > > > Signed-off-by: Frank Li > > > > > --- > > > > > .../devicetree/bindings/usb/snps,dwc3.yaml | 36 +++++++++++++= ++++++ > > > > > 1 file changed, 36 insertions(+) > > > > >=20 > > > > > diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml= b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > index 8f5d250070c78..43e7fea3f6798 100644 > > > > > --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml > > > > > @@ -439,6 +439,42 @@ properties: > > > > > items: > > > > > enum: [1, 4, 8, 16, 32, 64, 128, 256] > > > > > =20 > > > > > + snps,des-wr-reqinfo: > > > > > + description: Value for DESEWRREQIN of GSBUSCFG0 register. > > > > > + ----------------------------------------------------------= ------ > > > > > + MBUS_TYPE| bit[3] |bit[2] |bit[1] |bit[0] > > > > > + ----------------------------------------------------------= ------ > > > > > + AHB |Cacheable |Bufferable |Privilegge |Data > > > > > + AXI3 |Write Allocate|Read Allocate|Cacheable |Buffer= able > > > > > + AXI4 |Allocate Other|Allocate |Modifiable |Buffer= able > > > > > + AXI4 |Other Allocate|Allocate |Modifiable |Buffer= able > > > > > + Native |Same as AXI |Same as AXI |Same as AXI|Same a= s AXI > > > > > + ----------------------------------------------------------= ------ > > > > > + The AHB, AXI3, AXI4, and PCIe busses use different names f= or certain > > > > > + signals, which have the same meaning: > > > > > + Bufferable =3D Posted > > > > > + Cacheable =3D Modifiable =3D Snoop (negation of No Snoop) > > > > > + $ref: /schemas/types.yaml#/definitions/uint8 > > > > > + maxItem: 15 > > > > > + > > > > > + snps,des-rd-reqinfo: > > > > > + description: Value for DESRDREQIN of GSBUSCFG0 register. ref > > > > > + snps,des-wr-reqinfo > > > > > + $ref: /schemas/types.yaml#/definitions/uint8 > > > > > + maxItem: 15 > > > > > + > > > > > + snps,dat-wr-reqinfo: > > > > > + description: Value for DATWRREQIN of GSBUSCFG0 register. ref > > > > > + snps,des-wr-reqinfo > > > > > + $ref: /schemas/types.yaml#/definitions/uint8 > > > > > + maxItem: 15 > > > > > + > > > > > + snps,des-wr-reqinfo: > > > > > + description: Value for DATWRREQIN of GSBUSCFG0 register. ref > > > > > + snps,des-wr-reqinfo > > > > > + $ref: /schemas/types.yaml#/definitions/uint8 > > > > > + maxItem: 15 > > > > > + > > > > > num-hc-interrupters: > > > > > maximum: 8 > > > > > default: 1 > > > > > --=20 > > > > > 2.34.1 > > > > >=20 > > >=20 > > >=20 >=20 >=20 --gjo83bA3bLxaSiQd Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZbAIkwAKCRB4tDGHoIJi 0l5GAP93pP2+n9c7Ngq/2+2ZuBy0n/72VkccR8Xbv37y/t5J7AEA8kXs+aWNxxUF VyPexfs8f5y1gAB5zsysERG64YvLhgk= =ndMa -----END PGP SIGNATURE----- --gjo83bA3bLxaSiQd--