From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f176.google.com ([209.85.192.176]:34942 "EHLO mail-pd0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673AbbDGAbm (ORCPT ); Mon, 6 Apr 2015 20:31:42 -0400 Received: by pddn5 with SMTP id n5so60481731pdd.2 for ; Mon, 06 Apr 2015 17:31:41 -0700 (PDT) Message-ID: <1428366696.22268.28.camel@axtens.net> Subject: Re: [PATCH v2 04/19] powerpc: Create pci_controller_ops.dma_dev_setup and shim From: Daniel Axtens To: Arnd Bergmann Cc: linuxppc-dev@lists.ozlabs.org, wangyijing@huawei.com, linux-pci@vger.kernel.org Date: Tue, 07 Apr 2015 10:31:36 +1000 In-Reply-To: <5500778.Q4t9Fg7Irn@wuerfel> References: <1427778057-9505-1-git-send-email-dja@axtens.net> <1427778057-9505-5-git-send-email-dja@axtens.net> <5500778.Q4t9Fg7Irn@wuerfel> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-TVh8S7fVsFWscyQVZw4D" Mime-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org List-ID: --=-TVh8S7fVsFWscyQVZw4D Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > Please see https://patchwork.ozlabs.org/patch/431333/ for related work. >=20 I'm familiar with that patch series - I've been helping Yijing get it up to speed on PowerPC. > I think it would be better not to introduce another architecture-specific > pci host bridge operations structure, but instead consolidate into > the one that is already there. We are also adding a generic way to set up > PCI DMA, so it would seems reasonable to hook into that place. I see what you're getting at, and I agree that we want to move towards generic operations.=20 However, I think this should go in as is at this point, for two main reasons: 1) This is a good midpoint that makes it easier to move to a generic structure. Our arch specific stuff is quirky and difficult. This patch series does a lot to reduce the complexity, and would make it very easy to move these ops into a generic structure at some future point.=20 2) Trying to go generic at this point risks making the change set so complex and wide ranging that it will really struggle to get in. For example, Yijing's patch set, despite not changing any of the quirky stuff in PowerPC, is already quite long, and will require agreement from a lot of people before it can go in. Much as I would like to have everything as generic as possible, if we were to try to do the whole job in one go, it'd become a big, difficult, messy patch set, and would be less likely to happen than if we were to do it in two steps. Regards, Daniel --=-TVh8S7fVsFWscyQVZw4D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: GPGTools - https://gpgtools.org iQIcBAABCAAGBQJVIyVoAAoJEPC3R3P2I92FTlwP/3Qk6njMhm/gy6E4+DVQ39Az JiXZQwdZ1ltTJDiDqSHLm3wPwRk/i/r4kGzX+dPCTVapMZTeyx4uKFGYqAkO5hnU bdsoL8GXS9zHFwItRUewoXAQOti7lQ4Zn4BKw4G0ir6dp3q1wlh1twc6d9jZ6c30 4OLTpnvvO0BXnLoDjSse64pKO/YlKPgSM2oXE2Nec9Pm6zG+JKUgcGiD+6vbfh+h RqRg42Epw8RMWSF099Mc3UGxwrWz/SJkIiXRUq9MOgcLZjolKx+UE160YUAHC/Ni 8PUE62k+wTYiqejTROVcgEwTth717j0UNy4sr0THBztghmH7Xf3qOGMhlL9GbFhf 5qpglbnNj+NfTS1sBycY8KguZsJ58Zj3eA9cq7InSso6+mfE46nYXlD55RmdwgHB aez4RfkLLzZ8GebzEPsmXX2KYnYqEtOYMba/Tx79r3FXjOj2xZCqtVursDZgb00y 0X0iNogP2YBDCKIfYflu783W4Nn3asxojehVOzGDr5Fg+ZCQMIKalrfdsKHVjLv1 PpKROQ5ITcVooyvwdPdwfK30iyV4axpn5wblMOXuDptLt1AF1pLHUI4a8RQJfVP/ EGvu+lIVneJqhMMeaCVLqOq0R+5Qy3CO+OFeBOxmBMgyAxPlVuSiV5WWvpgpdeP+ KD4XPEjZ5H5rQemoTUN6 =kHEb -----END PGP SIGNATURE----- --=-TVh8S7fVsFWscyQVZw4D-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-x233.google.com (mail-pd0-x233.google.com [IPv6:2607:f8b0:400e:c02::233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 2F7311A0406 for ; Tue, 7 Apr 2015 10:31:44 +1000 (AEST) Received: by pdea3 with SMTP id a3so60480156pde.3 for ; Mon, 06 Apr 2015 17:31:41 -0700 (PDT) Message-ID: <1428366696.22268.28.camel@axtens.net> Subject: Re: [PATCH v2 04/19] powerpc: Create pci_controller_ops.dma_dev_setup and shim From: Daniel Axtens To: Arnd Bergmann Date: Tue, 07 Apr 2015 10:31:36 +1000 In-Reply-To: <5500778.Q4t9Fg7Irn@wuerfel> References: <1427778057-9505-1-git-send-email-dja@axtens.net> <1427778057-9505-5-git-send-email-dja@axtens.net> <5500778.Q4t9Fg7Irn@wuerfel> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-TVh8S7fVsFWscyQVZw4D" Mime-Version: 1.0 Cc: wangyijing@huawei.com, linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , --=-TVh8S7fVsFWscyQVZw4D Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable > Please see https://patchwork.ozlabs.org/patch/431333/ for related work. >=20 I'm familiar with that patch series - I've been helping Yijing get it up to speed on PowerPC. > I think it would be better not to introduce another architecture-specific > pci host bridge operations structure, but instead consolidate into > the one that is already there. We are also adding a generic way to set up > PCI DMA, so it would seems reasonable to hook into that place. I see what you're getting at, and I agree that we want to move towards generic operations.=20 However, I think this should go in as is at this point, for two main reasons: 1) This is a good midpoint that makes it easier to move to a generic structure. Our arch specific stuff is quirky and difficult. This patch series does a lot to reduce the complexity, and would make it very easy to move these ops into a generic structure at some future point.=20 2) Trying to go generic at this point risks making the change set so complex and wide ranging that it will really struggle to get in. For example, Yijing's patch set, despite not changing any of the quirky stuff in PowerPC, is already quite long, and will require agreement from a lot of people before it can go in. Much as I would like to have everything as generic as possible, if we were to try to do the whole job in one go, it'd become a big, difficult, messy patch set, and would be less likely to happen than if we were to do it in two steps. Regards, Daniel --=-TVh8S7fVsFWscyQVZw4D Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: GPGTools - https://gpgtools.org iQIcBAABCAAGBQJVIyVoAAoJEPC3R3P2I92FTlwP/3Qk6njMhm/gy6E4+DVQ39Az JiXZQwdZ1ltTJDiDqSHLm3wPwRk/i/r4kGzX+dPCTVapMZTeyx4uKFGYqAkO5hnU bdsoL8GXS9zHFwItRUewoXAQOti7lQ4Zn4BKw4G0ir6dp3q1wlh1twc6d9jZ6c30 4OLTpnvvO0BXnLoDjSse64pKO/YlKPgSM2oXE2Nec9Pm6zG+JKUgcGiD+6vbfh+h RqRg42Epw8RMWSF099Mc3UGxwrWz/SJkIiXRUq9MOgcLZjolKx+UE160YUAHC/Ni 8PUE62k+wTYiqejTROVcgEwTth717j0UNy4sr0THBztghmH7Xf3qOGMhlL9GbFhf 5qpglbnNj+NfTS1sBycY8KguZsJ58Zj3eA9cq7InSso6+mfE46nYXlD55RmdwgHB aez4RfkLLzZ8GebzEPsmXX2KYnYqEtOYMba/Tx79r3FXjOj2xZCqtVursDZgb00y 0X0iNogP2YBDCKIfYflu783W4Nn3asxojehVOzGDr5Fg+ZCQMIKalrfdsKHVjLv1 PpKROQ5ITcVooyvwdPdwfK30iyV4axpn5wblMOXuDptLt1AF1pLHUI4a8RQJfVP/ EGvu+lIVneJqhMMeaCVLqOq0R+5Qy3CO+OFeBOxmBMgyAxPlVuSiV5WWvpgpdeP+ KD4XPEjZ5H5rQemoTUN6 =kHEb -----END PGP SIGNATURE----- --=-TVh8S7fVsFWscyQVZw4D--