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 A1DE4C433EF for ; Mon, 10 Jan 2022 09:28:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238618AbiAJJ2w (ORCPT ); Mon, 10 Jan 2022 04:28:52 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:43592 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238864AbiAJJ2o (ORCPT ); Mon, 10 Jan 2022 04:28:44 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 58D6560F40 for ; Mon, 10 Jan 2022 09:28:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B814CC36AEF; Mon, 10 Jan 2022 09:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641806922; bh=Zzw7XicHXwbphesdb2LPnS8aIVN7zN6lbm6VQJfpbPY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=V8DOh03saCM5Pf6E+a8EF5j3FVZbZbvt9xymzjGhNSQhMpWHQNTwwB0ZwfL1PYl9t ZqHj9DWXe+OfqTMavzpqBylPEoqjKhlqMhfWZ7axOLeCaWb1NDgU2+LTqbigWXhGML 2l0FzG6MWYAWh44ApjeExardfdbDHYy5sfAkG9ZueOP50l/qDU3eUj/BzEpZ+83okX xBm2SBtE0IbKCxdK7ze1DCnN9yiyOFB/re2fmMxhgeBJhNh3e3nqNzMbzu8DFmm7uQ xGGYjRlAB/JtCFRN/M26GF/gCNr0VvEPnHmEJ7RAe8BvZ52CkC88NaYaKvaubX7QqN sZrN8mOxh0IPQ== Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1n6qym-00H5tN-5A; Mon, 10 Jan 2022 09:28:40 +0000 MIME-Version: 1.0 Date: Mon, 10 Jan 2022 09:28:39 +0000 From: Marc Zyngier To: =?UTF-8?Q?Marek_Beh=C3=BAn?= Cc: Lorenzo Pieralisi , Bjorn Helgaas , pali@kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 23/23] PCI: aardvark: Make main irq_chip structure a static driver structure In-Reply-To: <20220110015018.26359-24-kabel@kernel.org> References: <20220110015018.26359-1-kabel@kernel.org> <20220110015018.26359-24-kabel@kernel.org> User-Agent: Roundcube Webmail/1.4.12 Message-ID: X-Sender: maz@kernel.org Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: kabel@kernel.org, lorenzo.pieralisi@arm.com, helgaas@kernel.org, pali@kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 2022-01-10 01:50, Marek Behún wrote: > Marc Zyngier says [1] that we should use struct irq_chip as a global > static struct in the driver. Even though the structure currently > contains a dynamic member (parent_device), Marc says [2] that he plans > to kill it and make the structure completely static. > > We have already converted others irq_chip structures in this driver in > this way, but we omitted this one because the .name member is > dynamically created from device's name, and the name is displayed in > sysfs, so changing it would break sysfs ABI. > > The rationale for changing the name (to "advk-INT") in spite of sysfs > ABI, and thus allowing to convert to a static structure, is that after > the other changes we made in this series, the IRQ chip is basically > something different: it no logner generates ERR and PME interrupts > (they > are generated by emulated bridge's rp_irq_chip). There is no 'is spite of the ABI'. If you don't understand why we don't break the ABI, you have an even bigger problem. So NAK to this patch, now and forever. Any change to the structure to make it read-only must allow the preservation of the existing names when they are generated by the driver. M. -- Jazz is not dead. It just smells funny... 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Mon, 10 Jan 2022 09:28:40 +0000 MIME-Version: 1.0 Date: Mon, 10 Jan 2022 09:28:39 +0000 From: Marc Zyngier To: =?UTF-8?Q?Marek_Beh=C3=BAn?= Cc: Lorenzo Pieralisi , Bjorn Helgaas , pali@kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 23/23] PCI: aardvark: Make main irq_chip structure a static driver structure In-Reply-To: <20220110015018.26359-24-kabel@kernel.org> References: <20220110015018.26359-1-kabel@kernel.org> <20220110015018.26359-24-kabel@kernel.org> User-Agent: Roundcube Webmail/1.4.12 Message-ID: X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: kabel@kernel.org, lorenzo.pieralisi@arm.com, helgaas@kernel.org, pali@kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220110_012845_138022_ED825225 X-CRM114-Status: GOOD ( 17.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gMjAyMi0wMS0xMCAwMTo1MCwgTWFyZWsgQmVow7puIHdyb3RlOgo+IE1hcmMgWnluZ2llciBz YXlzIFsxXSB0aGF0IHdlIHNob3VsZCB1c2Ugc3RydWN0IGlycV9jaGlwIGFzIGEgZ2xvYmFsCj4g c3RhdGljIHN0cnVjdCBpbiB0aGUgZHJpdmVyLiBFdmVuIHRob3VnaCB0aGUgc3RydWN0dXJlIGN1 cnJlbnRseQo+IGNvbnRhaW5zIGEgZHluYW1pYyBtZW1iZXIgKHBhcmVudF9kZXZpY2UpLCBNYXJj IHNheXMgWzJdIHRoYXQgaGUgcGxhbnMKPiB0byBraWxsIGl0IGFuZCBtYWtlIHRoZSBzdHJ1Y3R1 cmUgY29tcGxldGVseSBzdGF0aWMuCj4gCj4gV2UgaGF2ZSBhbHJlYWR5IGNvbnZlcnRlZCBvdGhl cnMgaXJxX2NoaXAgc3RydWN0dXJlcyBpbiB0aGlzIGRyaXZlciBpbgo+IHRoaXMgd2F5LCBidXQg d2Ugb21pdHRlZCB0aGlzIG9uZSBiZWNhdXNlIHRoZSAubmFtZSBtZW1iZXIgaXMKPiBkeW5hbWlj YWxseSBjcmVhdGVkIGZyb20gZGV2aWNlJ3MgbmFtZSwgYW5kIHRoZSBuYW1lIGlzIGRpc3BsYXll ZCBpbgo+IHN5c2ZzLCBzbyBjaGFuZ2luZyBpdCB3b3VsZCBicmVhayBzeXNmcyBBQkkuCj4gCj4g VGhlIHJhdGlvbmFsZSBmb3IgY2hhbmdpbmcgdGhlIG5hbWUgKHRvICJhZHZrLUlOVCIpIGluIHNw aXRlIG9mIHN5c2ZzCj4gQUJJLCBhbmQgdGh1cyBhbGxvd2luZyB0byBjb252ZXJ0IHRvIGEgc3Rh dGljIHN0cnVjdHVyZSwgaXMgdGhhdCBhZnRlcgo+IHRoZSBvdGhlciBjaGFuZ2VzIHdlIG1hZGUg aW4gdGhpcyBzZXJpZXMsIHRoZSBJUlEgY2hpcCBpcyBiYXNpY2FsbHkKPiBzb21ldGhpbmcgZGlm ZmVyZW50OiBpdCBubyBsb2duZXIgZ2VuZXJhdGVzIEVSUiBhbmQgUE1FIGludGVycnVwdHMgCj4g KHRoZXkKPiBhcmUgZ2VuZXJhdGVkIGJ5IGVtdWxhdGVkIGJyaWRnZSdzIHJwX2lycV9jaGlwKS4K ClRoZXJlIGlzIG5vICdpcyBzcGl0ZSBvZiB0aGUgQUJJJy4gSWYgeW91IGRvbid0IHVuZGVyc3Rh bmQgd2h5CndlIGRvbid0IGJyZWFrIHRoZSBBQkksIHlvdSBoYXZlIGFuIGV2ZW4gYmlnZ2VyIHBy b2JsZW0uCgpTbyBOQUsgdG8gdGhpcyBwYXRjaCwgbm93IGFuZCBmb3JldmVyLiBBbnkgY2hhbmdl IHRvIHRoZSBzdHJ1Y3R1cmUgdG8KbWFrZSBpdCByZWFkLW9ubHkgbXVzdCBhbGxvdyB0aGUgcHJl c2VydmF0aW9uIG9mIHRoZSBleGlzdGluZyBuYW1lcwp3aGVuIHRoZXkgYXJlIGdlbmVyYXRlZCBi eSB0aGUgZHJpdmVyLgoKICAgICAgICAgTS4KLS0gCkphenogaXMgbm90IGRlYWQuIEl0IGp1c3Qg c21lbGxzIGZ1bm55Li4uCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxp c3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0 aW5mby9saW51eC1hcm0ta2VybmVsCg==