Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755149AbbFBLxd (ORCPT ); Tue, 2 Jun 2015 07:53:33 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:57411 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753009AbbFBLxZ (ORCPT ); Tue, 2 Jun 2015 07:53:25 -0400 Message-ID: <556D977F.3000904@huawei.com> Date: Tue, 2 Jun 2015 19:46:07 +0800 From: Bintian User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Russell King - ARM Linux CC: Linus Walleij , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Catalin Marinas , Will Deacon , "devicetree@vger.kernel.org" , Rob Herring , =?UTF-8?B?UGF3ZcWCIE1vbGw=?= , Mark Rutland , "ijc+devicetree@hellion.org.uk" , Kumar Gala , "Kevin Hilman" , Mike Turquette , "Rob Herring" , Zhangfei Gao , Haojian Zhuang , Xu Wei , Jaehoon Chung , Olof Johansson , , Stephen Boyd , , , Tomeu Vizoso , Guodong Xu , , Tyler Baker , Kevin Hilman , Paul Bolle , "Arnd Bergmann" , Marc Zyngier , , , , , , , Xinwei Hu , , Yunlei He , XinWei Kong , , , Subject: Re: [PATCH v9 4/6] Documentation: DT: PL011: hi6220: add compatible string for Hisilicon designed UART References: <1432950661-23060-1-git-send-email-bintian.wang@huawei.com> <1432950661-23060-5-git-send-email-bintian.wang@huawei.com> <556D8B98.2040703@huawei.com> <20150602112424.GC2067@n2100.arm.linux.org.uk> In-Reply-To: <20150602112424.GC2067@n2100.arm.linux.org.uk> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.68.103] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2545 Lines: 62 Hello Russell, On 2015/6/2 19:24, Russell King - ARM Linux wrote: > On Tue, Jun 02, 2015 at 06:55:20PM +0800, Bintian wrote: >> On 2015/6/2 16:59, Linus Walleij wrote: >>> On Sat, May 30, 2015 at 3:50 AM, Bintian Wang wrote: >>> >>>> Hisilicon does some performance enhancements based on PL011(e.g. larger >>>> FIFO length), so add one compatible string "hisilicon,hi6220-uart" for >>> >>> That compatible string in the commit message is not even >>> the same as in the patch. >> The UART0 is PL011 compatible, the UART1/2 have some performance >> enhancements features, so based on Mark's suggestion and I add this >> compatible string just for future use. > > Please don't submit it with this series. > > This patch should not be part of this series, it should be part of the > series which modifies the PL011 driver, so it can be reviewed along with > those changes. I agree with you and it's OK to me to remove this patch now. Could you help to ack the reset patches or I should send the version 10 without this patch? > > Until then, I'm going to NAK this patch. > > The thing that worries me though is that the subject line says this > is a "Hisilicon *designed* UART". If Hisilicon _designed_ this UART, > presumably they have changed the *vendor* field of the UART ID _not_ > to indicate that ARM Ltd designed it? > > If they've merely modified the parameters, and given the ARM Ltd PL011 > a larger fifo, then there isn't really much of a problem - we've been > here before, except the vendor has had a real vendor ID for the field > (in the case of ST), plus we've had different FIFO lengths for ARM > hardware too (32 bytes instead of 16 for revision 3 and above.) I think there is problem with my subject description, it's ARM designed indeed and Hisilicon just did some performance enhancements but not for UART0 in hi6220. > Lastly, if you're not having to modify the PL011 driver in any way, > you don't need to have a compatible. In any case, you _shouldn't_ for > AMBA devices. AMBA does not match drivers based on OF compatible > strings, so using OF compatible strings with the AMBA bus is just wrong. > The AMBA compatible strings are there so that the generic OF code knows > how to create the devices. Right. Thank you Russell. BR, Bintian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/