From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH v1 2/5] extcon: Return -EPROBE_DEFER when extcon device is not found Date: Wed, 14 Nov 2018 18:13:37 +0900 Message-ID: <5BEBE741.6050101@samsung.com> References: <20181110181101.24557-1-andriy.shevchenko@linux.intel.com> <20181110181101.24557-2-andriy.shevchenko@linux.intel.com> <5BE8C821.5080002@samsung.com> <5BEB63C3.1020504@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT Return-path: In-reply-to: Sender: linux-kernel-owner@vger.kernel.org To: Andy Shevchenko Cc: Andy Shevchenko , MyungJoo Ham , USB , Felipe Balbi , Guenter Roeck , "Krogerus, Heikki" , rogerq@ti.com, Linux PM , "Rafael J. Wysocki" , Sebastian Reichel , Linux OMAP Mailing List , Darren Hart , Platform Driver , Greg Kroah-Hartman , Linux Kernel Mailing List , Chen-Yu Tsai , Hans de Goede List-Id: linux-omap@vger.kernel.org On 2018년 11월 14일 17:35, Andy Shevchenko wrote: > On Wed, Nov 14, 2018 at 1:53 AM Chanwoo Choi wrote: > >> I was thinking about again to change from NULL to EPROBE_DEFER. >> >> extcon_get_extcon_dev() function was almost called in the probe function. >> But, this function might be called on other position instead of probe. > > *Might be* sounds like a theoretical thing, care to share what is in you mind? > Current users and more important the new coming one are *all* doing the same. > >> ENODEV is more correct error instead of EPROBE_DEFER. > > So, you are proposing to continue duplicating conversion from ENODEV > to EPROBE_DEFER in *each* caller? The extcon core don't know the caller situation is in either probe() or other position in the caller driver. The caller driver should decide the kind of error value by using the return value of extcon_get_extcon_dev(). extcon_get_extcon_dev() function cannot be modified for only one case. If some device driver call extcon_get_extcon_dev() out of probe() fuction, EPROBE_DEFER is not always correct. > >> Sorry. I'll withdraw my opinion related acked-by tag until we are clarifying it. > > I honestly don't know what to clarify here. > > When we would have a real case we can change API correspondingly. > For now, the score is 5:0 with use cases in practice. > >> On 2018년 11월 12일 09:24, Chanwoo Choi wrote: >>> On 2018년 11월 11일 03:10, Andy Shevchenko wrote: >>>> All current users of extcon_get_extcon_dev() API considers >>>> an extcon device a mandatory to appear. Thus, they all convert >>>> NULL pointer to -EPROBE_DEFER error code. >>>> >>>> There is one more caller anticipated with the same requirements. >>>> >>>> To decrease a code duplication and a burden to the callers, >>>> return -EPROBE_DEFER directly from extcon_get_extcon_dev(). > -- Best Regards, Chanwoo Choi Samsung Electronics From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v1,2/5] extcon: Return -EPROBE_DEFER when extcon device is not found From: Chanwoo Choi Message-Id: <5BEBE741.6050101@samsung.com> Date: Wed, 14 Nov 2018 18:13:37 +0900 To: Andy Shevchenko Cc: Andy Shevchenko , MyungJoo Ham , USB , Felipe Balbi , Guenter Roeck , "Krogerus, Heikki" , rogerq@ti.com, Linux PM , "Rafael J. Wysocki" , Sebastian Reichel , Linux OMAP Mailing List , Darren Hart , Platform Driver , Greg Kroah-Hartman , Linux Kernel Mailing List , Chen-Yu Tsai , Hans de Goede List-ID: T24gMjAxOOuFhCAxMeyblCAxNOydvCAxNzozNSwgQW5keSBTaGV2Y2hlbmtvIHdyb3RlOgo+IE9u IFdlZCwgTm92IDE0LCAyMDE4IGF0IDE6NTMgQU0gQ2hhbndvbyBDaG9pIDxjdzAwLmNob2lAc2Ft c3VuZy5jb20+IHdyb3RlOgo+IAo+PiBJIHdhcyB0aGlua2luZyBhYm91dCBhZ2FpbiB0byBjaGFu Z2UgZnJvbSBOVUxMIHRvIEVQUk9CRV9ERUZFUi4KPj4KPj4gZXh0Y29uX2dldF9leHRjb25fZGV2 KCkgZnVuY3Rpb24gd2FzIGFsbW9zdCBjYWxsZWQgaW4gdGhlIHByb2JlIGZ1bmN0aW9uLgo+PiBC dXQsIHRoaXMgZnVuY3Rpb24gbWlnaHQgYmUgY2FsbGVkIG9uIG90aGVyIHBvc2l0aW9uIGluc3Rl YWQgb2YgcHJvYmUuCj4gCj4gKk1pZ2h0IGJlKiBzb3VuZHMgbGlrZSBhIHRoZW9yZXRpY2FsIHRo aW5nLCBjYXJlIHRvIHNoYXJlIHdoYXQgaXMgaW4geW91IG1pbmQ/Cj4gQ3VycmVudCB1c2VycyBh bmQgbW9yZSBpbXBvcnRhbnQgdGhlIG5ldyBjb21pbmcgb25lIGFyZSAqYWxsKiBkb2luZyB0aGUg c2FtZS4KPiAKPj4gRU5PREVWIGlzIG1vcmUgY29ycmVjdCBlcnJvciBpbnN0ZWFkIG9mIEVQUk9C RV9ERUZFUi4KPiAKPiBTbywgeW91IGFyZSBwcm9wb3NpbmcgdG8gY29udGludWUgZHVwbGljYXRp bmcgY29udmVyc2lvbiBmcm9tIEVOT0RFVgo+IHRvIEVQUk9CRV9ERUZFUiBpbiAqZWFjaCogY2Fs bGVyPwoKVGhlIGV4dGNvbiBjb3JlIGRvbid0IGtub3cgdGhlIGNhbGxlciBzaXR1YXRpb24gaXMg aW4gZWl0aGVyIHByb2JlKCkgb3Igb3RoZXIgcG9zaXRpb24KaW4gdGhlIGNhbGxlciBkcml2ZXIu IFRoZSBjYWxsZXIgZHJpdmVyIHNob3VsZCBkZWNpZGUgdGhlIGtpbmQgb2YgZXJyb3IgdmFsdWUK YnkgdXNpbmcgdGhlIHJldHVybiB2YWx1ZSBvZiBleHRjb25fZ2V0X2V4dGNvbl9kZXYoKS4KCmV4 dGNvbl9nZXRfZXh0Y29uX2RldigpIGZ1bmN0aW9uIGNhbm5vdCBiZSBtb2RpZmllZCBmb3Igb25s eSBvbmUgY2FzZS4KSWYgc29tZSBkZXZpY2UgZHJpdmVyIGNhbGwgZXh0Y29uX2dldF9leHRjb25f ZGV2KCkgb3V0IG9mIHByb2JlKCkgZnVjdGlvbiwKRVBST0JFX0RFRkVSIGlzIG5vdCBhbHdheXMg Y29ycmVjdC4KCj4gCj4+IFNvcnJ5LiBJJ2xsIHdpdGhkcmF3IG15IG9waW5pb24gcmVsYXRlZCBh Y2tlZC1ieSB0YWcgdW50aWwgd2UgYXJlIGNsYXJpZnlpbmcgaXQuCj4gCj4gSSBob25lc3RseSBk b24ndCBrbm93IHdoYXQgdG8gY2xhcmlmeSBoZXJlLgo+IAo+IFdoZW4gd2Ugd291bGQgaGF2ZSBh IHJlYWwgY2FzZSB3ZSBjYW4gY2hhbmdlIEFQSSBjb3JyZXNwb25kaW5nbHkuCj4gRm9yIG5vdywg dGhlIHNjb3JlIGlzIDU6MCB3aXRoIHVzZSBjYXNlcyBpbiBwcmFjdGljZS4KPiAKPj4gT24gMjAx OOuFhCAxMeyblCAxMuydvCAwOToyNCwgQ2hhbndvbyBDaG9pIHdyb3RlOgo+Pj4gT24gMjAxOOuF hCAxMeyblCAxMeydvCAwMzoxMCwgQW5keSBTaGV2Y2hlbmtvIHdyb3RlOgo+Pj4+IEFsbCBjdXJy ZW50IHVzZXJzIG9mIGV4dGNvbl9nZXRfZXh0Y29uX2RldigpIEFQSSBjb25zaWRlcnMKPj4+PiBh biBleHRjb24gZGV2aWNlIGEgbWFuZGF0b3J5IHRvIGFwcGVhci4gVGh1cywgdGhleSBhbGwgY29u dmVydAo+Pj4+IE5VTEwgcG9pbnRlciB0byAtRVBST0JFX0RFRkVSIGVycm9yIGNvZGUuCj4+Pj4K Pj4+PiBUaGVyZSBpcyBvbmUgbW9yZSBjYWxsZXIgYW50aWNpcGF0ZWQgd2l0aCB0aGUgc2FtZSBy ZXF1aXJlbWVudHMuCj4+Pj4KPj4+PiBUbyBkZWNyZWFzZSBhIGNvZGUgZHVwbGljYXRpb24gYW5k IGEgYnVyZGVuIHRvIHRoZSBjYWxsZXJzLAo+Pj4+IHJldHVybiAtRVBST0JFX0RFRkVSIGRpcmVj dGx5IGZyb20gZXh0Y29uX2dldF9leHRjb25fZGV2KCkuCj4K