From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:52918 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932893AbeFKP0W (ORCPT ); Mon, 11 Jun 2018 11:26:22 -0400 Received: by mail-wm0-f66.google.com with SMTP id p126-v6so15447448wmb.2 for ; Mon, 11 Jun 2018 08:26:21 -0700 (PDT) Subject: Re: [PATCH V3] ARM: shmobile: Rework the PMIC IRQ line quirk To: Geert Uytterhoeven Cc: Linux ARM , Geert Uytterhoeven , Kuninori Morimoto , Linux-Renesas , Wolfram Sang , Simon Horman , Marek Vasut 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> From: Marek Vasut Message-ID: <3eda9da7-e26e-3e77-1040-9febe3b18abb@gmail.com> Date: Mon, 11 Jun 2018 17:26:09 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: On 06/11/2018 04:30 PM, Geert Uytterhoeven wrote: > 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]). Yes, I want to keep a list of machines to check, to be _sure_ some machine doesn't randomly blow up. > Anyway, as we care about booting old DTBs on new kernels (for a while), we > have a few more release cycles to bikeshed ;-) I was about to ask if this patch then makes any sense or not. -- Best regards, Marek Vasut From mboxrd@z Thu Jan 1 00:00:00 1970 From: marek.vasut@gmail.com (Marek Vasut) Date: Mon, 11 Jun 2018 17:26:09 +0200 Subject: [PATCH V3] ARM: shmobile: Rework the PMIC IRQ line quirk In-Reply-To: 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: <3eda9da7-e26e-3e77-1040-9febe3b18abb@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/11/2018 04:30 PM, Geert Uytterhoeven wrote: > 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]). Yes, I want to keep a list of machines to check, to be _sure_ some machine doesn't randomly blow up. > Anyway, as we care about booting old DTBs on new kernels (for a while), we > have a few more release cycles to bikeshed ;-) I was about to ask if this patch then makes any sense or not. -- Best regards, Marek Vasut