From patchwork Mon Mar 14 11:54:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 551239 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 6BE0EC352A8 for ; Mon, 14 Mar 2022 12:22:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241735AbiCNMXd (ORCPT ); Mon, 14 Mar 2022 08:23:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243473AbiCNMUp (ORCPT ); Mon, 14 Mar 2022 08:20:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B218546A1; Mon, 14 Mar 2022 05:16:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D383860929; Mon, 14 Mar 2022 12:16:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E2EBC340E9; Mon, 14 Mar 2022 12:16:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647260167; bh=ElunhrL+NnN9HybiB6bM+2vs16utvqSOjpdCWcmh+X4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ILbsmcwL0XQkXwNPlMAHJt6GMHJaJ+NFWXTSPifAGjS61fFoB7hSo1ZsU5Cn2AK1Y RVI4W/s4hC2+2mnT2f3P3bA/sPl8x6KLBdowweulBLIbpPLkYK0P84zdE9XKQ/+WtM 5mCq1f7YVXC0F+YvX27xzAmmk6VlmZNAc4QCc2k4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Walleij , Andy Shevchenko , kernel test robot , Shreeya Patel , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 5.16 076/121] gpio: Return EPROBE_DEFER if gc->to_irq is NULL Date: Mon, 14 Mar 2022 12:54:19 +0100 Message-Id: <20220314112746.242564960@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220314112744.120491875@linuxfoundation.org> References: <20220314112744.120491875@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shreeya Patel [ Upstream commit ae42f9288846353982e2eab181fb41e7fd8bf60f ] We are racing the registering of .to_irq when probing the i2c driver. This results in random failure of touchscreen devices. Following explains the race condition better. [gpio driver] gpio driver registers gpio chip [gpio consumer] gpio is acquired [gpio consumer] gpiod_to_irq() fails with -ENXIO [gpio driver] gpio driver registers irqchip gpiod_to_irq works at this point, but -ENXIO is fatal We could see the following errors 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. Returning -EPROBE_DEFER would be the first step towards avoiding the failure of devices due to the race in registration of .to_irq. Final solution to this issue would be to avoid using gc irq members until they are fully initialized. 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. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=209413 Reviewed-by: Linus Walleij Reviewed-by: Andy Shevchenko Reported-by: kernel test robot Signed-off-by: Shreeya Patel Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a1dca6dc03b4..dcb0dca651ac 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3121,6 +3121,16 @@ int gpiod_to_irq(const struct gpio_desc *desc) return retirq; } +#ifdef CONFIG_GPIOLIB_IRQCHIP + 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; + } +#endif return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq);