From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 60C4AC433F5 for ; Mon, 13 Dec 2021 11:07:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=DfZlQNo2mzolhsS6W5eDzruoS3ZUbal6IF9Q0EsBafI=; b=Qd7TfS+TZQ7yel 5W3c/BLWzhN3bgGHuizXAzkvc03+ckx7y93KME8C68scHeR8D1xG0XjrxlrVc+c2xJzHacXS91zai otVzMbbspVb6HqkFLly1m32kZ4Y1nK54MbrfZj6Ss1jFHCi5c3evHMaAkOb/gUKtyX7Idx7jbWQMg eBmsXyNYs0RY75TCthjcTF6R8a9lBPtbVFICgxpsMG3xuMPRZMcQEhuvEYNqUhYU7PXQoyXKfHVyq HR4tR1O76+jXZf14NJmuuCZDSUWdurFtTZXcJxviSbfsOOkGz2Qm4VPjbKpxYcDVL7I3Jd0ZGIgJu p2PZlSt5lsaUzqFWJG1A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwjAh-009Aw8-NY; Mon, 13 Dec 2021 11:07:07 +0000 Received: from bhuna.collabora.co.uk ([46.235.227.227]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwjAe-009AvE-Az for linux-mtd@lists.infradead.org; Mon, 13 Dec 2021 11:07:05 +0000 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 0FB331F44952; Mon, 13 Dec 2021 11:07:02 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=collabora.com; s=mail; t=1639393622; bh=04bequcs/NusDXEPCLT88FK1oMcTVoR+NRtV8yyK19Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HPNa0pEfIv5hz6GQwg7ADSOI51qVUCd/TfMdvCH8ku4dokzLlTwYUlnHF+7KdlYVC es/+H7R0Wapod9i7t5ThTjnFFIPLAcnnWoAAjAp1aaBSMcUVmMOn+nTln1rkvFoCur GLWAgdzgdri+jR4cx8wNswkEeY7Op9czgpY97qLRd0JUWL7QWBiNJm8jnNNgiCVMME dMSSxK2M+9N2zlQ4HU+MLN59N0bjXqM/VePCWMoJwabqapJlGKVMBSYfc/LLeBIgWl lzVPj72aHm+EwDEEpZC7pc/BTaRun+PpKExRo/DnLECuZq7Mos0BWQ4BhiN0caVfQC VyhDvSBVm/OJw== Date: Mon, 13 Dec 2021 12:06:58 +0100 From: Boris Brezillon To: Sean Nyekjaer Cc: Miquel Raynal , linux-kernel@vger.kernel.org, Marek Szyprowski , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon , linux-mtd@lists.infradead.org Subject: Re: [PATCH v5 3/4] mtd: core: protect access to MTD devices while in suspend Message-ID: <20211213120658.45f312a6@collabora.com> In-Reply-To: <20211213105012.65jk4rylxzncqdfy@skn-laptop> References: <20211130132912.v6v45boce2zbnoy3@skn-laptop> <20211130143705.5d0404aa@collabora.com> <20211203143958.40645506@xps13> <20211209140721.6ki7gznvxwyn3cze@skn-laptop.hinnerup> <20211209152811.318bdf17@xps13> <20211210132535.gy7rqj5zblqlnz5y@skn-laptop.hadsten> <20211213101025.42c27b43@xps13> <20211213102801.569b50b1@collabora.com> <20211213103350.22590c13@xps13> <20211213105336.7be369b7@collabora.com> <20211213105012.65jk4rylxzncqdfy@skn-laptop> Organization: Collabora X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-redhat-linux-gnu) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211213_030704_573873_D19E9A33 X-CRM114-Status: GOOD ( 27.65 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org T24gTW9uLCAxMyBEZWMgMjAyMSAxMjo1MDoxMiArMDIwMApTZWFuIE55ZWtqYWVyIDxzZWFuQGdl YW5peC5jb20+IHdyb3RlOgoKPiBIaSBNaXF1ZWwgYW5kIEJvcmlzLAo+IAo+IE9uIE1vbiwgRGVj IDEzLCAyMDIxIGF0IDEwOjUzOjM2QU0gKzAxMDAsIEJvcmlzIEJyZXppbGxvbiB3cm90ZToKPiA+ IE9uIE1vbiwgMTMgRGVjIDIwMjEgMTA6MzM6NTAgKzAxMDAKPiA+IE1pcXVlbCBSYXluYWwgPG1p cXVlbC5yYXluYWxAYm9vdGxpbi5jb20+IHdyb3RlOgo+ID4gICAKPiA+ID4gSGVsbG8sCj4gPiA+ IAo+ID4gPiBib3Jpcy5icmV6aWxsb25AY29sbGFib3JhLmNvbSB3cm90ZSBvbiBNb24sIDEzIERl YyAyMDIxIDEwOjI4OjAxICswMTAwOgo+ID4gPiAgIAo+ID4gPiA+IE9uIE1vbiwgMTMgRGVjIDIw MjEgMTA6MTA6MjUgKzAxMDAKPiA+ID4gPiBNaXF1ZWwgUmF5bmFsIDxtaXF1ZWwucmF5bmFsQGJv b3RsaW4uY29tPiB3cm90ZToKPiA+ID4gPiAgICAgCj4gPiA+ID4gPiBIaSBTZWFuLAo+ID4gPiA+ ID4gCj4gPiA+ID4gPiBzZWFuQGdlYW5peC5jb20gd3JvdGUgb24gRnJpLCAxMCBEZWMgMjAyMSAx NDoyNTozNSArMDEwMDoKPiA+ID4gPiA+ICAgICAgIAo+ID4gPiA+ID4gPiBPbiBUaHUsIERlYyAw OSwgMjAyMSBhdCAwMzoyODoxMVBNICswMTAwLCBNaXF1ZWwgUmF5bmFsIHdyb3RlOiAgICAgICAg Cj4gPiA+ID4gPiA+ID4gSGkgU2VhbiwKPiA+ID4gPiA+ID4gPiAKPiA+ID4gPiA+ID4gPiBzZWFu QGdlYW5peC5jb20gd3JvdGUgb24gVGh1LCA5IERlYyAyMDIxIDE1OjA3OjIxICswMTAwOgo+ID4g PiA+ID4gPiA+ICAgICAgICAgICAKPiA+ID4gPiA+ID4gPiA+IE9uIEZyaSwgRGVjIDAzLCAyMDIx IGF0IDAyOjM5OjU4UE0gKzAxMDAsIE1pcXVlbCBSYXluYWwgd3JvdGU6ICAgICAgICAgIAo+ID4g PiA+ID4gPiA+ID4gPiBIZWxsbywKPiA+ID4gPiA+ID4gPiA+ID4gICAgICAgICAgICAgCj4gPiA+ ID4gPiA+ID4gPiA+ID4gPiBGaW5lIGJ5IG1lLCBsZXRzIGRyb3AgdGhpcyBzZXJpZXMuICAgICAg ICAgICAgCj4gPiA+ID4gPiA+ID4gPiA+IAo+ID4gPiA+ID4gPiA+ID4gPiBGWUkgSSd2ZSBkcm9w cGVkIHRoZSBlbnRpcmUgc2VyaWVzIGZyb20gbXRkL25leHQuIEknbSB3YWl0aW5nIGZvciB0aGUK PiA+ID4gPiA+ID4gPiA+ID4gZml4IGRpc2N1c3NlZCBiZWxvdyAod2l0aG91dCBhYnVzaW5nIHRo ZSBjaGlwIG11dGV4IDstKSApLiAgICAgICAgICAgIAo+ID4gPiA+ID4gPiA+ID4gCj4gPiA+ID4g PiA+ID4gPiBDb29sLCBsb29raW5nIGZvcndhcmQgdG8gdGVzdCBhIHBhdGNoIHNlcmllcyA6KSAg ICAgICAgICAKPiA+ID4gPiA+ID4gPiAKPiA+ID4gPiA+ID4gPiBUZXN0PyBZb3UgbWVhbiAid3Jp dGUiPyA6KQo+ID4gPiA+ID4gPiA+IAo+ID4gPiA+ID4gPiA+IENoZWVycywKPiA+ID4gPiA+ID4g PiBNaXF1w6hsICAgICAgICAgIAo+ID4gPiA+ID4gPiAKPiA+ID4gPiA+ID4gSGkgTWlxdWVsLAo+ ID4gPiA+ID4gPiAKPiA+ID4gPiA+ID4gU2hvdWxkIHdlIHVzIGEgYXRvbWljIGZvciB0aGUgc3Vz cGVuZGVkIHZhcmlhYmxlPyAgICAgICAgCj4gPiA+ID4gPiAKPiA+ID4gPiA+IEkgaGF2ZW4ndCB0 aG91Z2h0IGFib3V0IGl0IGV4dGVuc2l2ZWx5LCBhbiBhdG9taWMgdmFyaWFibGUgc291bmQgZmlu ZQo+ID4gPiA+ID4gYnV0IEkgYW0gZGVmaW5pdGVseSBub3QgYSBsb2NraW5nIGV4cGVydC4uLiAg ICAgIAo+ID4gPiA+IAo+ID4gPiA+IE5vIG5lZWQgdG8gdXNlIGFuIGF0b21pYyBpZiB0aGUgdmFy aWFibGUgaXMgYWxyZWFkeSBwcm90ZWN0ZWQgYnkgYSBsb2NrCj4gPiA+ID4gd2hlbiBhY2Nlc3Nl ZCwgYW5kIHRoaXMgc2VlbXMgdG8gYmUgY2FzZS4gICAgCj4gPiA+IAo+ID4gPiBNYXliZSB0aGVy ZSB3YXMgYSBjb25mdXNpb24gYWJvdXQgdGhpcyBsb2NrOiBJIHRoaW5rIEJvcmlzIGp1c3QgZG8g bm90Cj4gPiA+IHdhbnQgdGhlIGNvcmUgdG8gdGFrZSBhbnkgbG9jayBkdXJpbmcgYSBzdXNwZW5k IG9wZXJhdGlvbi4gQnV0IHlvdSBjYW4KPiA+ID4gc3RpbGwgdXNlIGxvY2tzLCBhcyBsb25nIGFz IHlvdSByZWxlYXNlIHRoZW0gYmVmb3JlIHN1c3BlbmRpbmcuCj4gPiA+IAo+ID4gPiBBbmQgYWxz bywgdGhhdCBjaGlwIGxvY2sgbWlnaHQgbm90IGJlIHRoZSBvbmUgeW91IHdhbnQgdG8gdGFrZSBi ZWNhdXNlCj4gPiA+IGl0J3MgYmVlbiBpbnRyb2R1Y2VkIGZvciBhbm90aGVyIHB1cnBvc2UuICAK PiA+IAo+ID4gQWNjZXNzIHRvIHRoZSBzdXNwZW5kZWQgZmllbGQgaXMgYWxyZWFkeSBwcm90ZWN0 ZWQgYnkgdGhlIGNoaXAgbG9jaywKPiA+IGFuZCBJIHRoaW5rIGl0J3MganVzdCBmaW5lIHRvIGtl ZXAgaXQgdGhpcyB3YXkuICAKPiAKPiBJJ20gcmVhZGluZyB0aGUgc3VzcGVuZGVkIHZhcmlhYmxl IGluIHdhaXRfZXZlbnQoKSBvdXRzaWRlIHRoZSBsb2NrIDovCgpJdCBkb2Vzbid0IG1hdHRlciBi ZWNhdXNlIHlvdSdyZSBjaGVja2luZyBpdCBhZ2FpbiB3aXRoIHRoZSBsb2NrIGhlbGQKd2hlbiBk b2luZyBhIG5ldyBsb29wIGl0ZXJhdGlvbi4KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fXwpMaW51eCBNVEQgZGlzY3Vzc2lvbiBtYWlsaW5nIGxp c3QKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1tdGQv Cg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D358C433EF for ; Mon, 13 Dec 2021 11:07:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233734AbhLMLHG (ORCPT ); Mon, 13 Dec 2021 06:07:06 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:37340 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231629AbhLMLHF (ORCPT ); Mon, 13 Dec 2021 06:07:05 -0500 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 0FB331F44952; Mon, 13 Dec 2021 11:07:02 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=collabora.com; s=mail; t=1639393622; bh=04bequcs/NusDXEPCLT88FK1oMcTVoR+NRtV8yyK19Y=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HPNa0pEfIv5hz6GQwg7ADSOI51qVUCd/TfMdvCH8ku4dokzLlTwYUlnHF+7KdlYVC es/+H7R0Wapod9i7t5ThTjnFFIPLAcnnWoAAjAp1aaBSMcUVmMOn+nTln1rkvFoCur GLWAgdzgdri+jR4cx8wNswkEeY7Op9czgpY97qLRd0JUWL7QWBiNJm8jnNNgiCVMME dMSSxK2M+9N2zlQ4HU+MLN59N0bjXqM/VePCWMoJwabqapJlGKVMBSYfc/LLeBIgWl lzVPj72aHm+EwDEEpZC7pc/BTaRun+PpKExRo/DnLECuZq7Mos0BWQ4BhiN0caVfQC VyhDvSBVm/OJw== Date: Mon, 13 Dec 2021 12:06:58 +0100 From: Boris Brezillon To: Sean Nyekjaer Cc: Miquel Raynal , linux-kernel@vger.kernel.org, Marek Szyprowski , Richard Weinberger , Vignesh Raghavendra , Boris Brezillon , linux-mtd@lists.infradead.org Subject: Re: [PATCH v5 3/4] mtd: core: protect access to MTD devices while in suspend Message-ID: <20211213120658.45f312a6@collabora.com> In-Reply-To: <20211213105012.65jk4rylxzncqdfy@skn-laptop> References: <20211130132912.v6v45boce2zbnoy3@skn-laptop> <20211130143705.5d0404aa@collabora.com> <20211203143958.40645506@xps13> <20211209140721.6ki7gznvxwyn3cze@skn-laptop.hinnerup> <20211209152811.318bdf17@xps13> <20211210132535.gy7rqj5zblqlnz5y@skn-laptop.hadsten> <20211213101025.42c27b43@xps13> <20211213102801.569b50b1@collabora.com> <20211213103350.22590c13@xps13> <20211213105336.7be369b7@collabora.com> <20211213105012.65jk4rylxzncqdfy@skn-laptop> Organization: Collabora X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 13 Dec 2021 12:50:12 +0200 Sean Nyekjaer wrote: > Hi Miquel and Boris, >=20 > On Mon, Dec 13, 2021 at 10:53:36AM +0100, Boris Brezillon wrote: > > On Mon, 13 Dec 2021 10:33:50 +0100 > > Miquel Raynal wrote: > > =20 > > > Hello, > > >=20 > > > boris.brezillon@collabora.com wrote on Mon, 13 Dec 2021 10:28:01 +010= 0: > > > =20 > > > > On Mon, 13 Dec 2021 10:10:25 +0100 > > > > Miquel Raynal wrote: > > > > =20 > > > > > Hi Sean, > > > > >=20 > > > > > sean@geanix.com wrote on Fri, 10 Dec 2021 14:25:35 +0100: > > > > > =20 > > > > > > On Thu, Dec 09, 2021 at 03:28:11PM +0100, Miquel Raynal wrote: = =20 > > > > > > > Hi Sean, > > > > > > >=20 > > > > > > > sean@geanix.com wrote on Thu, 9 Dec 2021 15:07:21 +0100: > > > > > > > =20 > > > > > > > > On Fri, Dec 03, 2021 at 02:39:58PM +0100, Miquel Raynal wro= te: =20 > > > > > > > > > Hello, > > > > > > > > > =20 > > > > > > > > > > > Fine by me, lets drop this series. =20 > > > > > > > > >=20 > > > > > > > > > FYI I've dropped the entire series from mtd/next. I'm wai= ting for the > > > > > > > > > fix discussed below (without abusing the chip mutex ;-) )= . =20 > > > > > > > >=20 > > > > > > > > Cool, looking forward to test a patch series :) =20 > > > > > > >=20 > > > > > > > Test? You mean "write"? :) > > > > > > >=20 > > > > > > > Cheers, > > > > > > > Miqu=C3=A8l =20 > > > > > >=20 > > > > > > Hi Miquel, > > > > > >=20 > > > > > > Should we us a atomic for the suspended variable? =20 > > > > >=20 > > > > > I haven't thought about it extensively, an atomic variable sound = fine > > > > > but I am definitely not a locking expert... =20 > > > >=20 > > > > No need to use an atomic if the variable is already protected by a = lock > > > > when accessed, and this seems to be case. =20 > > >=20 > > > Maybe there was a confusion about this lock: I think Boris just do not > > > want the core to take any lock during a suspend operation. But you can > > > still use locks, as long as you release them before suspending. > > >=20 > > > And also, that chip lock might not be the one you want to take because > > > it's been introduced for another purpose. =20 > >=20 > > Access to the suspended field is already protected by the chip lock, > > and I think it's just fine to keep it this way. =20 >=20 > I'm reading the suspended variable in wait_event() outside the lock :/ It doesn't matter because you're checking it again with the lock held when doing a new loop iteration.