From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751112AbdCQQGB (ORCPT ); Fri, 17 Mar 2017 12:06:01 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:60237 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751010AbdCQQF5 (ORCPT ); Fri, 17 Mar 2017 12:05:57 -0400 X-AuditID: b6c32a2e-f79d66d0000012ad-4e-58cc05f45e4b From: Bartlomiej Zolnierkiewicz To: Tejun Heo Cc: Russell King , Sergei Shtylyov , Sekhar Nori , Arnd Bergmann , Dmitry Eremin-Solenikov , Kevin Hilman , Olof Johansson , linux-ide@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] pata_pcmcia: add EBSA110's PCMCIA slot support Date: Fri, 17 Mar 2017 16:51:13 +0100 Message-id: <5827966.LxfQpi93qC@amdc3058> User-Agent: KMail/4.13.3 (Linux/3.13.0-96-generic; KDE/4.13.3; x86_64; ; ) In-reply-to: <20170317141313.GC5078@htj.duckdns.org> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset=us-ascii X-Brightmail-Tracker: H4sIAAAAAAAAA01Sa0hTYRjuO2eX43J5nJdeFBUGGWqakcJRM7pInepHEYGmUM48eEnn2FFJ i7Kg1gVLV5oNEwvtMkxlTp2JLhW1bEZe8LLQ1DTCSH+Y5N3mzgT/Pc/7Ps/7fA98BC5p4bsR SfJ0RimXpUgFIl5dm4+v/1++KSqw6FsItaruEFLqyVmcWlTpMUr3Y4BPdRgmMKrvfbGAMuZW Y1TX4JyA6n2Uj1EmrVlILb1uR4e2030DPTi9vKRG9OzQbSE9VrCO0Q2aESGt094T0DVlN+j+ j7f4dOdQPUbP6TzPiKJFB+KZlKRMRrn3YKwosXLgDU8x4nrFYCzl56AFx/vIjgAyCObeFQk4 7ApfR6ssWERIyHIEz7+s2IgKg7f6YXzT8V3dinOLYgSfmtU2Mo+g7MFn3oZKQIZCvkqLNrAz 6QH9heNoQ4ST6xhUNpmtgU7kUejr/Wk18MhdkPcrB9vAYtIHVuqHrBoX8iTom1XWuZ0lerG7 GnEaR1h4PGr14qQXNBsL+BzeA90dldYwIP8IIWd90WImLMQDdB9sFSJg4lmDrbQTTHfqhRx2 h9VyM+LwUwT1y8DdqUGgbcyzicKgrbPHFrYDcpcnbffFcPeOhJPQ0DT9zyY/DE/aufdIyFcI VjVTeB7y0mzpoNnSQbOlQynCtciVUbCpCQwbrNgfwMpS2Qx5QsCltFQdsn4s3wADWis91YpI AkntxQvbTFESviyTzUptRUDgUmdxC7KMxPGyrGxGmXZRmZHCsK3IneBJd4qjA/OjJGSCLJ25 zDAKRrm5xQg7txwUZxpuqNVNT4XenE6emaioqI2tjimRm9lBn3OO3jJ5ZPKxI/bn88e7HE54 GcrTk8JVVOTA0pyD2qSIqwu/0FiUG2II9jFdO+2qcHmo2j1BNPdnuyT0h54tWaCdqrz1V2Mi ChOjSyo914xBETFhM2Ce9/czXn8R2PJy7Hepn+64lMcmyvb54kpW9h+5WDZrVAMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrMIsWRmVeSWpSXmKPExsVy+t9jQd0vrGciDF7NEbD4O+kYu8WkJ++Z LX62b2Gy2PT4GqvFsR2PmCwu75rDZrG/dwOTxanrn9ksLvVPZLI4s+oWu8Wv5UcZHbg9Ll+7 yOzx+9ckRo/3N1rZPR5M/c/ksXPWXXaPTas62Tw2L6n3uHKiidXj+I3tTB6fN8kFcEW52WSk JqakFimk5iXnp2TmpdsqhYa46VooKeQl5qbaKkXo+oYEKSmUJeaUAnlGBmjAwTnAPVhJ3y7B LWPdtRUsBXfFKnbsX8DawPhDsIuRk0NCwETi/qRDzBC2mMSFe+vZuhi5OIQEZjFK9C58yQzh fGWUuPTzNTtIFZuAlcTE9lWMILaIgKzElWkPGUGKmAUamSXO/L7FBJIQFnCWuHzpGQuIzSKg KjHhRQNYnFdAU+LP9htsILaogJfEln3tYHFOoDN+nt3ACLFtBaPExCN72CEaBCV+TL4HNohZ QF5i3/6prBC2lsT6nceZJjACHYpQNgtJ2SwkZQsYmVcxSqQWJBcUJ6XnGuWllusVJ+YWl+al 6yXn525iBEfwM+kdjId3uR9iFOBgVOLhvfHkdIQQa2JZcWXuIUYJDmYlEd6DjGcihHhTEiur Uovy44tKc1KLDzGaAn04kVlKNDkfmFzySuINTcxNzI0NLMwtLU2MlMR5G2c/CxcSSE8sSc1O TS1ILYLpY+LglGpg7DkllfUqxGTv/Rv+OlsqrTh7P9RpNKWdCKhyuHe4b+Uh0WfbXhWpfz27 Pza7yeywlNeJ7zdkJnefX1/oqZKcej538rSE7nvxqhZBOXzc1zw2TXqSvzn9m1n8t633e7JS 1+nU5OWkeN9OkDU5dWFlhlu7vGfWWml9/+XfXvzIlpjypVbm+9edSizFGYmGWsxFxYkA3kpJ tPYCAAA= X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20170317155116epcas5p2398eba5883fcee31b297c584fdc1885d X-Msg-Generator: CA X-Sender-IP: 203.254.230.27 X-Local-Sender: =?UTF-8?B?QmFydGxvbWllaiBab2xuaWVya2lld2ljehtTUlBPTC1LZXJu?= =?UTF-8?B?ZWwgKFRQKRvsgrzshLHsoITsnpAbU2VuaW9yIFNvZnR3YXJlIEVuZ2luZWVy?= X-Global-Sender: =?UTF-8?B?QmFydGxvbWllaiBab2xuaWVya2lld2ljehtTUlBPTC1LZXJu?= =?UTF-8?B?ZWwgKFRQKRtTYW1zdW5nIEVsZWN0cm9uaWNzG1NlbmlvciBTb2Z0d2FyZSBF?= =?UTF-8?B?bmdpbmVlcg==?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjczOTI=?= CMS-TYPE: 105P X-HopCount: 7 X-CMS-RootMailID: 20170314175046epcas1p43f98daad14a2bac7f314e7d39e120232 X-RootMTR: 20170314175046epcas1p43f98daad14a2bac7f314e7d39e120232 References: <11380780.Ccg1NEX8q5@amdc3058> <20170317141313.GC5078@htj.duckdns.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, March 17, 2017 10:13:13 AM Tejun Heo wrote: > Hello, > > On Fri, Mar 17, 2017 at 03:08:56PM +0100, Bartlomiej Zolnierkiewicz wrote: > > To be honest, the main point here is to make Russell happy. ;-) > > > > This is the second time he brought EBSA110 issue while talking about > > conversion of ARM platforms to use libata PATA so I've finally decided > > to do the patch just to have a reference example of how to deal with > > this and similar devices in a proper way. > > > > Even though the patch can't be tested EBSA110 is still a supported ARM > > platform and the patch should work fine in theory (+ it cannot break > > anything). OTOH it adds an extra code which has some cost from the > > long-term maintenance POV. Anyway, it is up to you to decide what to > > do with it. :-) > > It's fairly low impact and I don't think it's gonna add noticeable > maintenance overhead at all, so that part is fine but it's super weird > to add code which we know not to have any users. It looks like we > can't even test it. Well, this is more general problem. We keep things like ARM EBSA110 platform support in the kernel for some reason.. maybe we shouldn't? > What's the end game here? Is it part of the effort to remove ide? If > so, I have no objection to that but think it isn't a pressing issue > either and the ultimate decision has to come from Dave. I'm just helping in migrating users that are still using ide to libata, enhancing libata's hardware support in the process. I would prefer to have ide removed in the long-term (once there are no known users of it) but Dave has a valid point (see below). This particular patch is more a by-product of the above work than a part of it itself. Dave's current opinion is that we can't prove that all configurations currently supported by ide are supported by libata. Since it can never be really proved (as there are ide drivers for hardware that cannot be tested because of having no active users) he is fine with ide staying in the kernel forever. Which may be not as bad for me personally as I have a lot of contributions there. ;-) Theoretically another option is to finish ide's evolution into "ide compat" layer for SCSI/libata. This would give us full git history from ide to libata support + thin compatibility layer. However with libata PATA availability and hardware being obsolete there is no real need for it and the cost to finish such transition is much higher than cost of ide staying in the kernel forever. Moreover it would need to happen outside of the upstream kernel and there are no guarantees that it would be ever merged (ide is in deep maintenance policy and treated as a "safe fallback" for libata; SCSI & libata changes would need to be agreed on). Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics