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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 94414C433DB for ; Thu, 18 Feb 2021 18:02:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EF1264EB1 for ; Thu, 18 Feb 2021 18:02:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234947AbhBRSBo (ORCPT ); Thu, 18 Feb 2021 13:01:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:38652 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230340AbhBRPWL (ORCPT ); Thu, 18 Feb 2021 10:22:11 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 4CB24AD57; Thu, 18 Feb 2021 15:21:28 +0000 (UTC) To: Christoph Hellwig Cc: Greg KH , Daniel Vetter , David Airlie , dri-devel , USB list , Linux Kernel Mailing List References: <20210218150746.GA18220@lst.de> From: Thomas Zimmermann Subject: Re: Regression: 6eb0233ec2d0 ("usb: don't inherity DMA properties for USB devices") Message-ID: Date: Thu, 18 Feb 2021 16:21:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210218150746.GA18220@lst.de> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="VSWlDvtYdfOL7Tl8R4iE5C8FzFqKh6JnP" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --VSWlDvtYdfOL7Tl8R4iE5C8FzFqKh6JnP Content-Type: multipart/mixed; boundary="mJWIti817m0Z6jMfS36ap1UGHc6CI4WQi"; protected-headers="v1" From: Thomas Zimmermann To: Christoph Hellwig Cc: Greg KH , Daniel Vetter , David Airlie , dri-devel , USB list , Linux Kernel Mailing List Message-ID: Subject: Re: Regression: 6eb0233ec2d0 ("usb: don't inherity DMA properties for USB devices") References: <20210218150746.GA18220@lst.de> In-Reply-To: <20210218150746.GA18220@lst.de> --mJWIti817m0Z6jMfS36ap1UGHc6CI4WQi Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Am 18.02.21 um 16:07 schrieb Christoph Hellwig: > On Thu, Feb 18, 2021 at 03:56:00PM +0100, Thomas Zimmermann wrote: >> I only have udl devices, but I expect that other DRM USB adapters are = also >> affected. >=20 > Find where the driver calls dma_map_* itself instead of using the USB > wrappers and fix that.. >=20 Sure, it's at [1]. For udl, the dmabuf would need to be in system=20 memory. The driver creates urbs from the framebuffer content and sends=20 them to the device for displaying. My question is more: what's the best interface to do this? Is there=20 example code somewhere? Best regards Thomas [1]=20 https://elixir.bootlin.com/linux/v5.11/source/drivers/gpu/drm/drm_prime.c= #L630 --=20 Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany (HRB 36809, AG N=C3=BCrnberg) Gesch=C3=A4ftsf=C3=BChrer: Felix Imend=C3=B6rffer --mJWIti817m0Z6jMfS36ap1UGHc6CI4WQi-- --VSWlDvtYdfOL7Tl8R4iE5C8FzFqKh6JnP Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsF5BAABCAAjFiEExndm/fpuMUdwYFFolh/E3EQov+AFAmAuhfYFAwAAAAAACgkQlh/E3EQov+DA 6A//QdhPXebD7M+EzYUQ/FPnqUMNZAPP2uEP6VWwQQg1LkyhE45S3Cij4JD0ulGEvFZ63QMIAOz6 U+eHXkKSX8vum5Ns9lHXgaQLiF+30j+FeB47XKWNNyBGJwysN5lIe4RI63CA30fJC+PEZGsNGPnk 7wh1Fvp2mgo5SAe0OsZB/5D030s7sV48YQ2dU0z8vIdsNGWVseuRf12oq6jlB18KOW4Ypw5J6o0/ HSc+uMqAVhNyDDTUVNqkOQobgZ0uyjoaj0rdonUcCXOPQHDc6HeU2eeKMgAD87xrLw2h/Ghl2z+F aQl8WTb7+NsE1sW8jjx0bhIBPj0K1A+v5HN2NdhycbUbnEHhaeVnzvO5sdn2hPVBc3rWfAl3+2Ax pK/KtpSoqZv4dagLcLMVDwXbGOPKqCIGEizPXr58t2gKV7SrTTILb22FVQv9nTIu1foRKyyUaaSz Y+djErr5PMrAf78kBAJ8UFFz6RZ5TxDypzkqSeifhZWziz9ZSf7MExV+ZHGQZ2lXonOp4RuK3+6p 89OHWkSdZL/SH0VcrbpZDiGh9Iyur1KMjo6kndylvXJPh31ZuBHEGglNSAPP6888XefHunWjlx/N nw4l8F54ln8byP0IWJGJ7VVHRYWaxU6R+4FjhwWs/TJsoSZ/i4H/p7m5kFQRG8mqBMbRefVJtWfg xQw= =bR7v -----END PGP SIGNATURE----- --VSWlDvtYdfOL7Tl8R4iE5C8FzFqKh6JnP--