From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua0-f196.google.com ([209.85.217.196]:44728 "EHLO mail-ua0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932298AbeFKObK (ORCPT ); Mon, 11 Jun 2018 10:31:10 -0400 Received: by mail-ua0-f196.google.com with SMTP id f30-v6so13653470uab.11 for ; Mon, 11 Jun 2018 07:31:10 -0700 (PDT) MIME-Version: 1.0 References: <20180604175911.799-1-marek.vasut+renesas@gmail.com> <967b800e-c935-aa35-da5a-ca3672fd18c2@gmail.com> <47e87deb-a7a8-4780-53b5-4e4ed6e1bac3@gmail.com> <6864ed2c-39ac-615d-f38e-b28c3647e451@gmail.com> In-Reply-To: <6864ed2c-39ac-615d-f38e-b28c3647e451@gmail.com> From: Geert Uytterhoeven Date: Mon, 11 Jun 2018 16:30:58 +0200 Message-ID: Subject: Re: [PATCH V3] ARM: shmobile: Rework the PMIC IRQ line quirk To: Marek Vasut Cc: Linux ARM , Geert Uytterhoeven , Kuninori Morimoto , Linux-Renesas , Wolfram Sang , Simon Horman , Marek Vasut Content-Type: text/plain; charset="UTF-8" Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi Marek, On Mon, Jun 11, 2018 at 4:19 PM Marek Vasut wrote: > On 06/11/2018 04:10 PM, Geert Uytterhoeven wrote: > > On Mon, Jun 11, 2018 at 4:04 PM Marek Vasut wrote: > >> On 06/11/2018 03:49 PM, Geert Uytterhoeven wrote: > >>> On Mon, Jun 11, 2018 at 3:39 PM Marek Vasut wrote: > >>>> On 06/11/2018 03:03 PM, Geert Uytterhoeven wrote: > >>>>> On Mon, Jun 11, 2018 at 2:15 PM Marek Vasut wrote: > >>>>>> On 06/11/2018 11:56 AM, Geert Uytterhoeven wrote: > >>>>>>> On Mon, Jun 4, 2018 at 7:59 PM Marek Vasut wrote: > >>>>>>>> Rather than hard-coding the quirk topology, which stopped scaling, > >>>>>>>> parse the information from DT. The code looks for all compatible > >>>>>>>> PMICs -- da9036 and da9210 -- and checks if their IRQ line is tied > >>>>>>>> to the same pin. If so, the code sends a matching sequence to the > >>>>>>>> PMIC to deassert the IRQ. > >>> > >>>>>>>> + ret = of_property_read_u32(np, "reg", &addr); > >>>>>>>> + if (ret) > >>>>>>>> + return ret; > >>>>>>> > >>>>>>> I think it's safer to skip this entry and continue, after calling > >>>>>>> kfree(quirk), of course. > >>>>>>> > >>>>>>>> + > >>>>>>>> + quirk->id = id; > >>>>>>>> + quirk->i2c_msg.addr = addr; > >>>>>>>> + quirk->shared = false; > >>>>>>>> + > >>>>>>>> + ret = of_irq_parse_one(np, 0, &quirk->irq_args); > >>>>>>>> + if (ret) > >>>>>>>> + return ret; > >>>>>>> > >>>>>>> kfree(quirk) and continue... > >>>>>> > >>>>>> I wonder if it shouldn't rather free the entire list and abort ? > >>>>> > >>>>> "Be strict when sending, be liberal when receiving." > >>>> > >>>> Meaning ? I think "the language barrier is protecting me" (TM) > >>> > >>> Do the best you can, given the buggy DT you received. > >>> I.e. don't fail completely, just ignore the bad device node, and continue. > >> > >> But if you ignore node, you might as well ignore one which is shared and > >> then the system crashes due to IRQ storm anyway. So hum, what can we do ? > > > > Correct. If it's a critical node, it will crash regardless. > > If it's a non-critical node, you have the choice between aborting and crashing, > > or ignoring and keeping the system alive. Your call. > > But wait, since we control which machines this code runs on , can't we > assure they have valid DTs ? This situation with invalid DT starts to > look a bit hypothetical to me. That assumes you keep the list of machines to check, and don't want to fix the issue automatically when detected (on any R-Car Gen2 or RZ/G1 platform, so you still need to check for r8a779[0-4] and r8a774[23457]). Anyway, as we care about booting old DTBs on new kernels (for a while), we have a few more release cycles to bikeshed ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Mon, 11 Jun 2018 16:30:58 +0200 Subject: [PATCH V3] ARM: shmobile: Rework the PMIC IRQ line quirk In-Reply-To: <6864ed2c-39ac-615d-f38e-b28c3647e451@gmail.com> References: <20180604175911.799-1-marek.vasut+renesas@gmail.com> <967b800e-c935-aa35-da5a-ca3672fd18c2@gmail.com> <47e87deb-a7a8-4780-53b5-4e4ed6e1bac3@gmail.com> <6864ed2c-39ac-615d-f38e-b28c3647e451@gmail.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Marek, On Mon, Jun 11, 2018 at 4:19 PM Marek Vasut wrote: > On 06/11/2018 04:10 PM, Geert Uytterhoeven wrote: > > On Mon, Jun 11, 2018 at 4:04 PM Marek Vasut wrote: > >> On 06/11/2018 03:49 PM, Geert Uytterhoeven wrote: > >>> On Mon, Jun 11, 2018 at 3:39 PM Marek Vasut wrote: > >>>> On 06/11/2018 03:03 PM, Geert Uytterhoeven wrote: > >>>>> On Mon, Jun 11, 2018 at 2:15 PM Marek Vasut wrote: > >>>>>> On 06/11/2018 11:56 AM, Geert Uytterhoeven wrote: > >>>>>>> On Mon, Jun 4, 2018 at 7:59 PM Marek Vasut wrote: > >>>>>>>> Rather than hard-coding the quirk topology, which stopped scaling, > >>>>>>>> parse the information from DT. The code looks for all compatible > >>>>>>>> PMICs -- da9036 and da9210 -- and checks if their IRQ line is tied > >>>>>>>> to the same pin. If so, the code sends a matching sequence to the > >>>>>>>> PMIC to deassert the IRQ. > >>> > >>>>>>>> + ret = of_property_read_u32(np, "reg", &addr); > >>>>>>>> + if (ret) > >>>>>>>> + return ret; > >>>>>>> > >>>>>>> I think it's safer to skip this entry and continue, after calling > >>>>>>> kfree(quirk), of course. > >>>>>>> > >>>>>>>> + > >>>>>>>> + quirk->id = id; > >>>>>>>> + quirk->i2c_msg.addr = addr; > >>>>>>>> + quirk->shared = false; > >>>>>>>> + > >>>>>>>> + ret = of_irq_parse_one(np, 0, &quirk->irq_args); > >>>>>>>> + if (ret) > >>>>>>>> + return ret; > >>>>>>> > >>>>>>> kfree(quirk) and continue... > >>>>>> > >>>>>> I wonder if it shouldn't rather free the entire list and abort ? > >>>>> > >>>>> "Be strict when sending, be liberal when receiving." > >>>> > >>>> Meaning ? I think "the language barrier is protecting me" (TM) > >>> > >>> Do the best you can, given the buggy DT you received. > >>> I.e. don't fail completely, just ignore the bad device node, and continue. > >> > >> But if you ignore node, you might as well ignore one which is shared and > >> then the system crashes due to IRQ storm anyway. So hum, what can we do ? > > > > Correct. If it's a critical node, it will crash regardless. > > If it's a non-critical node, you have the choice between aborting and crashing, > > or ignoring and keeping the system alive. Your call. > > But wait, since we control which machines this code runs on , can't we > assure they have valid DTs ? This situation with invalid DT starts to > look a bit hypothetical to me. That assumes you keep the list of machines to check, and don't want to fix the issue automatically when detected (on any R-Car Gen2 or RZ/G1 platform, so you still need to check for r8a779[0-4] and r8a774[23457]). Anyway, as we care about booting old DTBs on new kernels (for a while), we have a few more release cycles to bikeshed ;-) Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds