From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792774629; b=IdiXYCwi1nK8iIGWF+zUbeI6XO3m276+5H7pTAn7T3R3pQ8Yx6j7j4WXM95GGhHfUqPQ HJnqE2l2BGN/j+Yxwj02Qvfcfe2HC56aAfQ5ay1q9SfrCw4nH6Lfj2MDp3MxOUNv34Q6A 9sgUdBy+7kLG6XfmlkBZQdYhVgeimG462Sg+tnCOOa+sQK545TSBo/L8NHaRAwCiz1yam px480QTdge6IEp2ryBJYDYCSjzQSuuHDtQENevuMOgKx7K2xOnvoJG46zADxr5LCETHjS 4AYCywoOUKusFkED4yzTZ+4jO8a2rlMiFbXjdLp3mFF+6gKM1PCkI/7pLvR0LXSJGNg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792774629; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=2ja579bQvDKsK4F5HXWaNBk73gbAgjto9VJ6mL282Sk=; b=pc0ZoToMvlI+dhxUBVXcNNDohWcYNgxM9LfIKZXG0ycoLVzqAQNWkdxEOR3qxcXDW+Sn G4UADTpgnTYLMkBq3QzdZ33byRRywhtIOa76rHwLuE9Owy2uBZU5WOnyCw0ntWW3nPji9 /+DeUtUaiSp448jqCEgXmNZAhgkeSnHkgsIGXd8c9ar+DyqlnC/3vekUO1Hc2wJ2MIL6W vIds8BtVThi80FmyTM1ZTrKlLIl8Q/oRIklXnii13zPdy3oiqQDpKFFLATsuAzo5hyjer KtPLFRiYF6Ge6g8lCNF2OZ1/f7IGOLJzXtul4qcU8pA3U2i0RSGpjHfw/xA2/DlXOXg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=CS8eQZRB; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5AC18606A31F; Fri, 23 Oct 2026 16:57:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=CS8eQZRB Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E2661F01825; Fri, 23 Oct 2026 16:57:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792774629; bh=2ja579bQvDKsK4F5HXWaNBk73gbAgjto9VJ6mL282Sk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CS8eQZRBp41B1TufZ9xZ9ZOX392V0fSMLjoW5aqlHYJ+A6ZO2QuyaF7qiI8+1F4HU VtQjrTiwUNtTlDvEAuuUg0wn4rrGgLhblo+tluUTKOHaLXJMcKHHk64jsxmg0fMwm0 095LG6wkbztHsC62jNk0bWQno5xcy2d99SadcrpU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Li , Peng Fan , Andy Shevchenko , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 7.2 088/242] gpio: mxc: fix wakeup_pads bit operations Date: Fri, 23 Oct 2026 18:38:50 +0200 Message-ID: <20261023163715.859798630@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261023163713.816071858@linuxfoundation.org> References: <20261023163713.816071858@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peng Fan [ Upstream commit 170aeff46fb54f41545c85a72aec525aebc79d44 ] gpio_set_wake_irq() can be called concurrently for different pins on the same port. The writer-vs-writer race is the concern: two concurrent gpio_set_wake_irq() calls for different pins on the same port both do a non-atomic read-modify-write on the same wakeup_pads word. The old |= and &= compile to separate load/modify/store instructions that can interleave, losing one CPU's update. assign_bit() uses an atomic RMW instruction, so concurrent writers to different bits in the same word are safe. The reader side (for_each_set_bit in noirq_suspend, wakeup_pads > 0) runs in noirq context where no concurrent writer can execute, so reader atomicity is not needed. wakeup_pads is a u32, while assign_bit() operates on unsigned long pointers. On 64-bit platforms, this causes an 8-byte read-modify-write on a 4-byte field, corrupting the adjacent is_pad_wakeup. So change wakeup_pads to unsigned long and reorder to avoid wasting words. And fix the enable/disable path unconditionally sets/clears the wakeup_pads bit even when enable_irq_wake()/disable_irq_wake() fails. Only update the bit on success. Fixes: f60c9eac54af ("gpio: mxc: enable pad wakeup on i.MX8x platforms") Assisted-by: LLM Reviewed-by: Frank Li Signed-off-by: Peng Fan Reviewed-by: Andy Shevchenko Link: https://patch.msgid.link/20261013-gpio-mxc-cleanup-v7-3-c4d769587d3e@nxp.com Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/gpio/gpio-mxc.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpio/gpio-mxc.c b/drivers/gpio/gpio-mxc.c index 7e17d7668980d..e3a80f17d0412 100644 --- a/drivers/gpio/gpio-mxc.c +++ b/drivers/gpio/gpio-mxc.c @@ -72,8 +72,8 @@ struct mxc_gpio_port { unsigned long both_edges; struct mxc_gpio_reg_saved gpio_saved_reg; bool power_off; - u32 wakeup_pads; bool is_pad_wakeup; + unsigned long wakeup_pads; u32 pad_type[32]; const struct mxc_gpio_hwdata *hwdata; }; @@ -331,16 +331,18 @@ static int gpio_set_wake_irq(struct irq_data *d, u32 enable) ret = enable_irq_wake(port->irq_high); else ret = enable_irq_wake(port->irq); - port->wakeup_pads |= BIT(gpio_idx); } else { if (port->irq_high && (gpio_idx >= 16)) ret = disable_irq_wake(port->irq_high); else ret = disable_irq_wake(port->irq); - port->wakeup_pads &= ~BIT(gpio_idx); } + if (ret) + return ret; - return ret; + assign_bit(gpio_idx, &port->wakeup_pads, enable); + + return 0; } static int mxc_gpio_init_gc(struct mxc_gpio_port *port, int irq_base) -- 2.53.0