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 4A103C83F17 for ; Mon, 28 Aug 2023 10:21:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230107AbjH1KVK (ORCPT ); Mon, 28 Aug 2023 06:21:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229999AbjH1KUl (ORCPT ); Mon, 28 Aug 2023 06:20:41 -0400 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8229CCEB for ; Mon, 28 Aug 2023 03:20:14 -0700 (PDT) Received: by mail-lf1-x12b.google.com with SMTP id 2adb3069b0e04-4fe61ae020bso4554148e87.2 for ; Mon, 28 Aug 2023 03:20:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1693218011; x=1693822811; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=cvoOITWtFaNG9POgyW2mF9j8Nw/ZFb+8+V0tdCk2Wrs=; b=PDEoA1CgaH3JBNLP4OI69JrUISJzVSa0wszoHtPiKnO+qynjXqmZV7czsVCjfeYOXw 27VhbVYhXhULpJZZbEbg2GOlEvw9xKqrtweVsPNpb6mIYsWRk5K4oLVxs9iwMvrU1y7/ Y3W949T+SGPoXXRUAFoBlokNL7hfC/NQLUKv16VZjvbxX997iFBsbxQ/ZLhEC71pQlXB gPvhD4ZM9JcPZ03ThSElkjlQm6XwaDdXKSzIq5kGZLDCV1BebHwTJtaVk47wxc6DvPN/ 10v8Ha1APilB49mfe9I21v7tCxBHsYaF+Vyt2inUEUUo4IZD2aY8yyB+fbbO8HgY3lFp aaag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693218011; x=1693822811; h=content-transfer-encoding:in-reply-to:autocrypt:from:references:cc :to:content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cvoOITWtFaNG9POgyW2mF9j8Nw/ZFb+8+V0tdCk2Wrs=; b=OYiqwSabyJPri8pE88bhM2jr9kWMPMRe7ti2urQ8b5DNJkrVjKjLxMwTrGWZiKMYQq tAf7v3tsoRD66WaMLCJGl1NR1rOggURvXfeI3tN8gFXc/6OpiEG+h4w8Siu5xROIoUJU DBa9ylzH0qB49bCA/2fhlrC5uPHH8pvFldALrMkYE7uaERDOOyMglGNiox6yA6fFARAV coAJ5pz0QdJIvo+TBJxk9sXUknhJCaALKCYLgxi8RBebTwzYqXHvu9lNoxAkno1/giIn BwhTMngylK/u4qBrquzOwUm2pFtCPt++tn3N0iO2aSwr2gHozvuXOLAWmlIbbJVJbNo4 BHww== X-Gm-Message-State: AOJu0YwIO6ujBDkGOY1QEyjHENz1Gp4TanvRJg0EIS35vd1C7YreMg9n XgpzjOpnvR9qQLmAnuDWauaRzw== X-Google-Smtp-Source: AGHT+IGOmOYMHsHLMpmbGBNUWNAqmHNZVUvHB3LgOdAD1xiIwjirxbzn+XXMQjcAeR4q3Amxi6qTEw== X-Received: by 2002:ac2:562f:0:b0:4f8:5755:5b22 with SMTP id b15-20020ac2562f000000b004f857555b22mr16670646lff.27.1693218010994; Mon, 28 Aug 2023 03:20:10 -0700 (PDT) Received: from [192.168.1.101] (abyl195.neoplus.adsl.tpnet.pl. [83.9.31.195]) by smtp.gmail.com with ESMTPSA id m13-20020ac2424d000000b004fea9cf6a32sm1520604lfl.204.2023.08.28.03.20.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Aug 2023 03:20:10 -0700 (PDT) Message-ID: <8876d95c-e7ea-478a-bb88-b97e5cf67f08@linaro.org> Date: Mon, 28 Aug 2023 12:20:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] irqchip/qcom-pdc: don't read version register if it is not available Content-Language: en-US To: Marc Zyngier , Dmitry Baryshkov Cc: "Maulik Shah (mkshah)" , Andy Gross , Bjorn Andersson , Thomas Gleixner , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Neil Armstrong References: <20230825213552.1646321-1-dmitry.baryshkov@linaro.org> <09d89b1c-8c78-7671-a385-99c6a8910fde@quicinc.com> <865y4zfppf.wl-maz@kernel.org> From: Konrad Dybcio Autocrypt: addr=konrad.dybcio@linaro.org; keydata= xsFNBF9ALYUBEADWAhxdTBWrwAgDQQzc1O/bJ5O7b6cXYxwbBd9xKP7MICh5YA0DcCjJSOum BB/OmIWU6X+LZW6P88ZmHe+KeyABLMP5s1tJNK1j4ntT7mECcWZDzafPWF4F6m4WJOG27kTJ HGWdmtO+RvadOVi6CoUDqALsmfS3MUG5Pj2Ne9+0jRg4hEnB92AyF9rW2G3qisFcwPgvatt7 TXD5E38mLyOPOUyXNj9XpDbt1hNwKQfiidmPh5e7VNAWRnW1iCMMoKqzM1Anzq7e5Afyeifz zRcQPLaqrPjnKqZGL2BKQSZDh6NkI5ZLRhhHQf61fkWcUpTp1oDC6jWVfT7hwRVIQLrrNj9G MpPzrlN4YuAqKeIer1FMt8cq64ifgTzxHzXsMcUdclzq2LTk2RXaPl6Jg/IXWqUClJHbamSk t1bfif3SnmhA6TiNvEpDKPiT3IDs42THU6ygslrBxyROQPWLI9IL1y8S6RtEh8H+NZQWZNzm UQ3imZirlPjxZtvz1BtnnBWS06e7x/UEAguj7VHCuymVgpl2Za17d1jj81YN5Rp5L9GXxkV1 aUEwONM3eCI3qcYm5JNc5X+JthZOWsbIPSC1Rhxz3JmWIwP1udr5E3oNRe9u2LIEq+wH/toH kpPDhTeMkvt4KfE5m5ercid9+ZXAqoaYLUL4HCEw+HW0DXcKDwARAQABzShLb25yYWQgRHli Y2lvIDxrb25yYWQuZHliY2lvQGxpbmFyby5vcmc+wsGOBBMBCAA4FiEEU24if9oCL2zdAAQV R4cBcg5dfFgFAmQ5bqwCGwMFCwkIBwIGFQoJCAsCBBYCAwECHgECF4AACgkQR4cBcg5dfFjO BQ//YQV6fkbqQCceYebGg6TiisWCy8LG77zV7DB0VMIWJv7Km7Sz0QQrHQVzhEr3trNenZrf yy+o2tQOF2biICzbLM8oyQPY8B///KJTWI2khoB8IJSJq3kNG68NjPg2vkP6CMltC/X3ohAo xL2UgwN5vj74QnlNneOjc0vGbtA7zURNhTz5P/YuTudCqcAbxJkbqZM4WymjQhe0XgwHLkiH 5LHSZ31MRKp/+4Kqs4DTXMctc7vFhtUdmatAExDKw8oEz5NbskKbW+qHjW1XUcUIrxRr667V GWH6MkVceT9ZBrtLoSzMLYaQXvi3sSAup0qiJiBYszc/VOu3RbIpNLRcXN3KYuxdQAptacTE mA+5+4Y4DfC3rUSun+hWLDeac9z9jjHm5rE998OqZnOU9aztbd6zQG5VL6EKgsVXAZD4D3RP x1NaAjdA3MD06eyvbOWiA5NSzIcC8UIQvgx09xm7dThCuQYJR4Yxjd+9JPJHI6apzNZpDGvQ BBZzvwxV6L1CojUEpnilmMG1ZOTstktWpNzw3G2Gis0XihDUef0MWVsQYJAl0wfiv/0By+XK mm2zRR+l/dnzxnlbgJ5pO0imC2w0TVxLkAp0eo0LHw619finad2u6UPQAkZ4oj++iIGrJkt5 Lkn2XgB+IW8ESflz6nDY3b5KQRF8Z6XLP0+IEdLOOARkOW7yEgorBgEEAZdVAQUBAQdAwmUx xrbSCx2ksDxz7rFFGX1KmTkdRtcgC6F3NfuNYkYDAQgHwsF2BBgBCAAgFiEEU24if9oCL2zd AAQVR4cBcg5dfFgFAmQ5bvICGwwACgkQR4cBcg5dfFju1Q//Xta1ShwL0MLSC1KL1lXGXeRM 8arzfyiB5wJ9tb9U/nZvhhdfilEDLe0jKJY0RJErbdRHsalwQCrtq/1ewQpMpsRxXzAjgfRN jc4tgxRWmI+aVTzSRpywNahzZBT695hMz81cVZJoZzaV0KaMTlSnBkrviPz1nIGHYCHJxF9r cIu0GSIyUjZ/7xslxdvjpLth16H27JCWDzDqIQMtg61063gNyEyWgt1qRSaK14JIH/DoYRfn jfFQSC8bffFjat7BQGFz4ZpRavkMUFuDirn5Tf28oc5ebe2cIHp4/kajTx/7JOxWZ80U70mA cBgEeYSrYYnX+UJsSxpzLc/0sT1eRJDEhI4XIQM4ClIzpsCIN5HnVF76UQXh3a9zpwh3dk8i bhN/URmCOTH+LHNJYN/MxY8wuukq877DWB7k86pBs5IDLAXmW8v3gIDWyIcgYqb2v8QO2Mqx YMqL7UZxVLul4/JbllsQB8F/fNI8AfttmAQL9cwo6C8yDTXKdho920W4WUR9k8NT/OBqWSyk bGqMHex48FVZhexNPYOd58EY9/7mL5u0sJmo+jTeb4JBgIbFPJCFyng4HwbniWgQJZ1WqaUC nas9J77uICis2WH7N8Bs9jy0wQYezNzqS+FxoNXmDQg2jetX8en4bO2Di7Pmx0jXA4TOb9TM izWDgYvmBE8= In-Reply-To: <865y4zfppf.wl-maz@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28.08.2023 12:04, Marc Zyngier wrote: > On Mon, 28 Aug 2023 10:46:10 +0100, > Dmitry Baryshkov wrote: >> >> On Mon, 28 Aug 2023 at 12:36, Maulik Shah (mkshah) >> wrote: >>> >>> Hi Dmitry, >>> >>> This patch may be useful if there was a case where some PDCs don't have >>> version register populated/available, >>> In all PDC versions, version register is always available but due to reg >>> size not good enough in device tree for SM8150 it failed to read. >>> >>> reg size in device node must be expanded if its too small to access all >>> registers and i think >>> additional check in driver to check if size is good enough would not be >>> of much use. >> >> Unfortunately, it doesn't work this way. DT files are ABI. Even if we >> change the DT, the kernel should continue working with the older >> version. >> Thus, we have to add such bandaid code, which will keep the kernel >> from crashing if old DT was used. > > You're missing the point: all existing PDC HW have version register. > The fact that the DT is crap doesn't invalidate this simple fact. It > is thus perfectly possible for the driver to *ignore* the crap and do > the right thing by expanding the size of the mapping, rather than > falling back to the non-versioned code. I wasn't sure if this would cross the "too hacky" boundary, but if you're fine with it, I'll happily ack this approach. Konrad