From patchwork Mon Oct 18 22:05:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shreeya Patel X-Patchwork-Id: 1542893 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by bilbo.ozlabs.org (Postfix) with ESMTP id 4HY9tR5K1Zz9sPf for ; Tue, 19 Oct 2021 09:05:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229555AbhJRWIB (ORCPT ); Mon, 18 Oct 2021 18:08:01 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:39594 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232139AbhJRWIB (ORCPT ); Mon, 18 Oct 2021 18:08:01 -0400 Received: from localhost.localdomain (unknown [IPv6:2401:4900:1c20:2044:d49c:4fd9:7471:bb74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: shreeya) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id EB76F1F432B7; Mon, 18 Oct 2021 23:05:45 +0100 (BST) From: Shreeya Patel To: linus.walleij@linaro.org, bgolaszewski@baylibre.com, wsa@kernel.org, krisman@collabora.com, sebastian.reichel@collabora.com Cc: kernel@collabora.com, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, Shreeya Patel Subject: [PATCH v2] gpio: Return EPROBE_DEFER if gc->to_irq is NULL Date: Tue, 19 Oct 2021 03:35:04 +0530 Message-Id: <20211018220504.8301-1-shreeya.patel@collabora.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org We are racing the registering of .to_irq when probing the i2c driver. This results in random failure of touchscreen devices. Following errors could be seen in dmesg logs when gc->to_irq is NULL [2.101857] i2c_hid i2c-FTS3528:00: HID over i2c has not been provided an Int IRQ [2.101953] i2c_hid: probe of i2c-FTS3528:00 failed with error -22 To avoid this situation, defer probing until to_irq is registered. This issue has been reported many times in past and people have been using workarounds like changing the pinctrl_amd to built-in instead of loading it as a module or by adding a softdep for pinctrl_amd into the config file. References :- https://bugzilla.kernel.org/show_bug.cgi?id=209413 https://github.com/Syniurge/i2c-amd-mp2/issues/3 Signed-off-by: Shreeya Patel Reviewed-by: Linus Walleij Reported-by: kernel test robot Reviewed-by: Andy Shevchenko --- Changes in v2 - Add a condition to check for irq chip to avoid bogus error. --- drivers/gpio/gpiolib.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 27c07108496d..12c088706167 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3084,6 +3084,14 @@ int gpiod_to_irq(const struct gpio_desc *desc) return retirq; } + if (gc->irq.chip) { + /* avoid race condition with other code, which tries to lookup + * an IRQ before the irqchip has been properly registered + * (i.e. while gpiochip is still being brought up). + */ + return -EPROBE_DEFER; + } + return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq);