From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v2 9/9] [media] omap3isp: support 64-bit version of omap3isp_stat_data Date: Mon, 09 Nov 2015 21:30:41 +0100 Message-ID: <3870339.ZAkvtJ2orM@wuerfel> References: <1442524780-781677-1-git-send-email-arnd@arndb.de> <1442524780-781677-10-git-send-email-arnd@arndb.de> <5733951.qvCn4pc5g5@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5733951.qvCn4pc5g5@avalon> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: y2038-bounces@lists.linaro.org Sender: "Y2038" To: y2038@lists.linaro.org Cc: linux-samsung-soc@vger.kernel.org, Mauro Carvalho Chehab , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Hans Verkuil , Laurent Pinchart , linux-media@vger.kernel.org List-Id: linux-api@vger.kernel.org T24gTW9uZGF5IDA5IE5vdmVtYmVyIDIwMTUgMjI6MDk6MjYgTGF1cmVudCBQaW5jaGFydCB3cm90 ZToKPiBIaSBBcm5kLAo+IAo+IFRoYW5rIHlvdSBmb3IgdGhlIHBhdGNoLgo+IAo+IE9uIFRodXJz ZGF5IDE3IFNlcHRlbWJlciAyMDE1IDIzOjE5OjQwIEFybmQgQmVyZ21hbm4gd3JvdGU6Cj4gPiBD IGxpYnJhcmllcyB3aXRoIDY0LWJpdCB0aW1lX3QgdXNlIGFuIGluY29tcGF0aWJsZSBmb3JtYXQg Zm9yCj4gPiBzdHJ1Y3Qgb21hcDNpc3Bfc3RhdF9kYXRhLiBUaGlzIGNoYW5nZXMgdGhlIGtlcm5l bCBjb2RlIHRvCj4gPiBzdXBwb3J0IGVpdGhlciB2ZXJzaW9uLCBieSBtb3Zpbmcgb3ZlciB0aGUg bm9ybWFsIGhhbmRsaW5nCj4gPiB0byB0aGUgNjQtYml0IHZhcmlhbnQsIGFuZCBhZGRpbmcgY29t cGF0aWJsaXR5IGNvZGUgdG8gaGFuZGxlCj4gPiB0aGUgb2xkIGJpbmFyeSBmb3JtYXQgd2l0aCB0 aGUgZXhpc3RpbmcgaW9jdGwgY29tbWFuZCBjb2RlLgo+ID4gCj4gPiBGb3J0dW5hdGVseSwgdGhl IGNvbW1hbmQgY29kZSBpbmNsdWRlcyB0aGUgc2l6ZSBvZiB0aGUgc3RydWN0dXJlLAo+ID4gc28g dGhlIGRpZmZlcmVuY2UgZ2V0cyBoYW5kbGVkIGF1dG9tYXRpY2FsbHkuCj4gCj4gV2UgcGxhbiB0 byBkZXNpZ24gYSBuZXcgaW50ZXJmYWNlIHRvIGhhbmRsZSBzdGF0aXN0aWNzIGluIFY0TDIuIFRo YXQgQVBJIAo+IHNob3VsZCBzdXBwb3J0IHByb3BlciA2NC1iaXQgdGltZXN0YW1wcyBvdXQgb2Yg dGhlIGJveCwgYW5kIHdpbGwgYmUgCj4gaW1wbGVtZW50ZWQgYnkgdGhlIE9NQVAzIElTUCBkcml2 ZXIuIFVzZXJzcGFjZSBzaG91bGQgdGhlbiBtb3ZlIHRvIGl0LiBJIAo+IHdvbmRlciBpZiBpdCdz IHdvcnRoIGl0IHRvIGZpeCB0aGUgZXhpc3RpbmcgVklESU9DX09NQVAzSVNQX1NUQVRfUkVRIGlv Y3RsIAo+IGdpdmVuIHRoYXQgSSBleHBlY3QgaXQgdG8gaGF2ZSBhIGhhbmRmdWwgb2YgdXNlcnMg YXQgbW9zdC4KCldlIHN0aWxsIG5lZWQgdG8gZG8gc29tZXRoaW5nIHRvIHRoZSBkcml2ZXIuIFRo ZSBhbHRlcm5hdGl2ZSB3b3VsZApiZSB0byBtYWtlIHRoZSBleGlzdGluZyBpb2N0bCBjb21tYW5k IG9wdGlvbmFsIGF0IGtlcm5lbCBjb21waWxlLXRpbWUKc28gd2UgY2FuIHN0aWxsIGJ1aWxkIHRo ZSBkcml2ZXIgb25jZSB3ZSByZW1vdmUgdGhlICdzdHJ1Y3QgdGltZXZhbCcKZGVmaW5pdGlvbi4g VGhhdCBwYXRjaCB3b3VsZCBhZGQgc2xpZ2h0bHkgbGVzcyBjb21wbGV4aXR5IGhlcmUKYnV0IGFs c28gbG9zZSBmdW5jdGlvbmFsaXR5LgoKQXMgbXkgcGF0Y2ggaGVyZSBkZXBlbmRzIG9uIHRoZSBz dHJ1Y3QgdjRsMl90aW1ldmFsIEkgaW50cm9kdWNlZCBpbgphbiBlYXJsaWVyIHBhdGNoIG9mIHRo ZSBzZXJpZXMsIHdlIHdpbGwgaGF2ZSB0byBjaGFuZ2UgaXQgYW55d2F5cywKYnV0IEknZCBwcmVm ZXIgdG8ga2VlcCB0aGUgYmFzaWMgaWRlYS4gTGV0J3MgZ2V0IGJhY2sgdG8gdGhpcyBvbmUKYWZ0 ZXIgdGhlIHY0bF9idWZmZXIgcmVwbGFjZW1lbnQgd29yayBpcyBkb25lLgoKCUFybmQKX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWTIwMzggbWFpbGluZyBs aXN0ClkyMDM4QGxpc3RzLmxpbmFyby5vcmcKaHR0cHM6Ly9saXN0cy5saW5hcm8ub3JnL21haWxt YW4vbGlzdGluZm8veTIwMzgK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mout.kundenserver.de ([212.227.17.13]:64629 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbbKIUa6 (ORCPT ); Mon, 9 Nov 2015 15:30:58 -0500 From: Arnd Bergmann To: y2038@lists.linaro.org Cc: Laurent Pinchart , linux-samsung-soc@vger.kernel.org, Mauro Carvalho Chehab , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Hans Verkuil , linux-media@vger.kernel.org Subject: Re: [Y2038] [PATCH v2 9/9] [media] omap3isp: support 64-bit version of omap3isp_stat_data Date: Mon, 09 Nov 2015 21:30:41 +0100 Message-ID: <3870339.ZAkvtJ2orM@wuerfel> In-Reply-To: <5733951.qvCn4pc5g5@avalon> References: <1442524780-781677-1-git-send-email-arnd@arndb.de> <1442524780-781677-10-git-send-email-arnd@arndb.de> <5733951.qvCn4pc5g5@avalon> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: On Monday 09 November 2015 22:09:26 Laurent Pinchart wrote: > Hi Arnd, > > Thank you for the patch. > > On Thursday 17 September 2015 23:19:40 Arnd Bergmann wrote: > > C libraries with 64-bit time_t use an incompatible format for > > struct omap3isp_stat_data. This changes the kernel code to > > support either version, by moving over the normal handling > > to the 64-bit variant, and adding compatiblity code to handle > > the old binary format with the existing ioctl command code. > > > > Fortunately, the command code includes the size of the structure, > > so the difference gets handled automatically. > > We plan to design a new interface to handle statistics in V4L2. That API > should support proper 64-bit timestamps out of the box, and will be > implemented by the OMAP3 ISP driver. Userspace should then move to it. I > wonder if it's worth it to fix the existing VIDIOC_OMAP3ISP_STAT_REQ ioctl > given that I expect it to have a handful of users at most. We still need to do something to the driver. The alternative would be to make the existing ioctl command optional at kernel compile-time so we can still build the driver once we remove the 'struct timeval' definition. That patch would add slightly less complexity here but also lose functionality. As my patch here depends on the struct v4l2_timeval I introduced in an earlier patch of the series, we will have to change it anyways, but I'd prefer to keep the basic idea. Let's get back to this one after the v4l_buffer replacement work is done. Arnd