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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B18BDC2D0C2 for ; Thu, 2 Jan 2020 17:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 789B12072C for ; Thu, 2 Jan 2020 17:40:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="Z+Tkx29q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727771AbgABRkY (ORCPT ); Thu, 2 Jan 2020 12:40:24 -0500 Received: from mail-qt1-f194.google.com ([209.85.160.194]:44015 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727706AbgABRkY (ORCPT ); Thu, 2 Jan 2020 12:40:24 -0500 Received: by mail-qt1-f194.google.com with SMTP id d18so32461526qtj.10 for ; Thu, 02 Jan 2020 09:40:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=+sRNYThXV/qw+oqY2hzFYFQkSAluAiDf3LujstPJXpk=; b=Z+Tkx29qHd99z3LbNVNdDV3VtbSq4poPWwpGVSq/8bOwWWJru2Np+4/MO3Eqi0M+/n XwsWUu4GiugfaKjmGWy5dcgYknIPmgQ8HSg+BQMFx1AKnQQ98ufVB32z11XFH3JmK67+ VmTtMu9erNzklKo5sGUNJ2CSRTaec8GjM3gpJuyyYkyESfBBsjtB4iQyHIduJuCnZoDF GHKxnjVyXJ8x6LKaFD3ZIn6h9YR0Sj58IUPVoAknxXgWCNKVAnJaoyCwWYMevzDAPSmo 8XhVUG04wcBsyryZCGDlnYuzweHgr82zQq9b9VbPxYxJOcsCjIX4PfJUpX6QNTqdSz95 1+Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=+sRNYThXV/qw+oqY2hzFYFQkSAluAiDf3LujstPJXpk=; b=QfmwI9eYI9Ih+de84xg9UovrsHbQ3lNR4ewhWh64fz81HuoP+/hn/kVFt8J+jnOMh6 JHEfkYAbQ+NZAgJqoQ0Kp9z1Nde8UqFVyi4rmu0g4k/rsv2EN75Ud9CZLtMVHGvgsYyV lrl0iAzT/nEx6T+89HGRxYfzHQDplRETV59MPk1byJdk/5Y6WrJFL04mIAE08b3T4Z2y OS98DU5Mdnph4i/pNL7mUDI8K/aWBBoNp6LjsgyVdsneCiWeUciR7OlpHI5rhNiB7ZGD LaMgAVrVOX7WihHzIAC8tPXJsZjmxf/YdYtdxKeUu0sJk8P9tg9gRSc/LbRoeAsP/W2q 88mQ== X-Gm-Message-State: APjAAAUw14ivRTxsRnYBc4ez8D9ff49HtU0npPWfeMwhqdY43hRzk2+3 HSaTdbHWHi1NFMWPJiypBDoQE87soHFmSQvR154GQQ== X-Google-Smtp-Source: APXvYqyNeaD4tk9QDs9WLgwv0+DhmaV3KGt2yAfjSv5ZOYVds8cpBjowJz2+eu1ZE3QJmZsgZSV/7gY4BE6Kfe4v6o0= X-Received: by 2002:ac8:704:: with SMTP id g4mr60782643qth.197.1577986823008; Thu, 02 Jan 2020 09:40:23 -0800 (PST) MIME-Version: 1.0 References: <1577362338-28744-1-git-send-email-srinivas.neeli@xilinx.com> <1577362338-28744-3-git-send-email-srinivas.neeli@xilinx.com> In-Reply-To: <1577362338-28744-3-git-send-email-srinivas.neeli@xilinx.com> From: Bartosz Golaszewski Date: Thu, 2 Jan 2020 18:40:12 +0100 Message-ID: Subject: Re: [PATCH 2/8] gpio: zynq: protect direction in/out with a spinlock To: Srinivas Neeli Cc: Linus Walleij , Michal Simek , shubhrajyoti.datta@xilinx.com, linux-gpio , arm-soc , LKML , git@xilinx.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org czw., 26 gru 2019 o 13:12 Srinivas Neeli napisa= =C5=82(a): > > From: Glenn Langedock > > Fix race condition when changing the direction (in/out) of the GPIO pin. > The read-modify-write sequence (as coded in the driver) isn't atomic and > requires synchronization (spinlock). > > Signed-off-by: Glenn Langedock > Signed-off-by: Michal Simek > Signed-off-by: Srinivas Neeli > --- > drivers/gpio/gpio-zynq.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c > index 05ba16fffdad..9c8b8a397a26 100644 > --- a/drivers/gpio/gpio-zynq.c > +++ b/drivers/gpio/gpio-zynq.c > @@ -10,6 +10,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -116,6 +117,7 @@ struct gpio_regs { > * @irq: interrupt for the GPIO device > * @p_data: pointer to platform data > * @context: context registers > + * @dirlock: lock used for direction in/out synchronization > */ > struct zynq_gpio { > struct gpio_chip chip; > @@ -124,6 +126,7 @@ struct zynq_gpio { > int irq; > const struct zynq_platform_data *p_data; > struct gpio_regs context; > + spinlock_t dirlock; /*lock used for direction in/out synchronizat= ion */ Maybe just call it 'lock' in case it turns out other operations need locking as well? 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charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Y3p3LiwgMjYgZ3J1IDIwMTkgbyAxMzoxMiBTcmluaXZhcyBOZWVsaSA8c3Jpbml2YXMubmVlbGlA eGlsaW54LmNvbT4gbmFwaXNhxYIoYSk6Cj4KPiBGcm9tOiBHbGVubiBMYW5nZWRvY2sgPEdsZW5u LkxhbmdlZG9ja0BiYXJjby5jb20+Cj4KPiBGaXggcmFjZSBjb25kaXRpb24gd2hlbiBjaGFuZ2lu ZyB0aGUgZGlyZWN0aW9uIChpbi9vdXQpIG9mIHRoZSBHUElPIHBpbi4KPiBUaGUgcmVhZC1tb2Rp Znktd3JpdGUgc2VxdWVuY2UgKGFzIGNvZGVkIGluIHRoZSBkcml2ZXIpIGlzbid0IGF0b21pYyBh bmQKPiByZXF1aXJlcyBzeW5jaHJvbml6YXRpb24gKHNwaW5sb2NrKS4KPgo+IFNpZ25lZC1vZmYt Ynk6IEdsZW5uIExhbmdlZG9jayA8R2xlbm4uTGFuZ2Vkb2NrQGJhcmNvLmNvbT4KPiBTaWduZWQt b2ZmLWJ5OiBNaWNoYWwgU2ltZWsgPG1pY2hhbC5zaW1la0B4aWxpbnguY29tPgo+IFNpZ25lZC1v ZmYtYnk6IFNyaW5pdmFzIE5lZWxpIDxzcmluaXZhcy5uZWVsaUB4aWxpbnguY29tPgo+IC0tLQo+ ICBkcml2ZXJzL2dwaW8vZ3Bpby16eW5xLmMgfCAxMSArKysrKysrKysrKwo+ICAxIGZpbGUgY2hh bmdlZCwgMTEgaW5zZXJ0aW9ucygrKQo+Cj4gZGlmZiAtLWdpdCBhL2RyaXZlcnMvZ3Bpby9ncGlv LXp5bnEuYyBiL2RyaXZlcnMvZ3Bpby9ncGlvLXp5bnEuYwo+IGluZGV4IDA1YmExNmZmZmRhZC4u OWM4YjhhMzk3YTI2IDEwMDY0NAo+IC0tLSBhL2RyaXZlcnMvZ3Bpby9ncGlvLXp5bnEuYwo+ICsr KyBiL2RyaXZlcnMvZ3Bpby9ncGlvLXp5bnEuYwo+IEBAIC0xMCw2ICsxMCw3IEBACj4gICNpbmNs dWRlIDxsaW51eC9ncGlvL2RyaXZlci5oPgo+ICAjaW5jbHVkZSA8bGludXgvaW5pdC5oPgo+ICAj aW5jbHVkZSA8bGludXgvaW50ZXJydXB0Lmg+Cj4gKyNpbmNsdWRlIDxsaW51eC9zcGlubG9jay5o Pgo+ICAjaW5jbHVkZSA8bGludXgvaW8uaD4KPiAgI2luY2x1ZGUgPGxpbnV4L21vZHVsZS5oPgo+ ICAjaW5jbHVkZSA8bGludXgvcGxhdGZvcm1fZGV2aWNlLmg+Cj4gQEAgLTExNiw2ICsxMTcsNyBA QCBzdHJ1Y3QgZ3Bpb19yZWdzIHsKPiAgICogQGlycTogICAgICAgaW50ZXJydXB0IGZvciB0aGUg R1BJTyBkZXZpY2UKPiAgICogQHBfZGF0YTogICAgcG9pbnRlciB0byBwbGF0Zm9ybSBkYXRhCj4g ICAqIEBjb250ZXh0OiAgIGNvbnRleHQgcmVnaXN0ZXJzCj4gKyAqIEBkaXJsb2NrOiAgIGxvY2sg dXNlZCBmb3IgZGlyZWN0aW9uIGluL291dCBzeW5jaHJvbml6YXRpb24KPiAgICovCj4gIHN0cnVj dCB6eW5xX2dwaW8gewo+ICAgICAgICAgc3RydWN0IGdwaW9fY2hpcCBjaGlwOwo+IEBAIC0xMjQs NiArMTI2LDcgQEAgc3RydWN0IHp5bnFfZ3BpbyB7Cj4gICAgICAgICBpbnQgaXJxOwo+ICAgICAg ICAgY29uc3Qgc3RydWN0IHp5bnFfcGxhdGZvcm1fZGF0YSAqcF9kYXRhOwo+ICAgICAgICAgc3Ry dWN0IGdwaW9fcmVncyBjb250ZXh0Owo+ICsgICAgICAgc3BpbmxvY2tfdCBkaXJsb2NrOyAvKmxv Y2sgdXNlZCBmb3IgZGlyZWN0aW9uIGluL291dCBzeW5jaHJvbml6YXRpb24gKi8KCk1heWJlIGp1 c3QgY2FsbCBpdCAnbG9jaycgaW4gY2FzZSBpdCB0dXJucyBvdXQgb3RoZXIgb3BlcmF0aW9ucyBu ZWVkCmxvY2tpbmcgYXMgd2VsbD8KCkJhcnQKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFy bS1rZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9t YWlsbWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK