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=1794590671; b=3LprGbuo9RRUQixriWZYM1htvqeeU7rHlNn0BTdiIWz+HX/5aXvyACxTw9hDSOPXBE/y 3ygchz7L2h74zYo93wMbAP7AHRoT2eJ2qvlOSsS79WurnAYWtuWi8s5bf6xEBDnu01r/y FA5l45wiLqWu2ehDbTa0gnUrXMilvFBvzFsKrrr0ItuTbDe30ARgNPVNdnBerB0VNkgiB vfi6OCLNfnZXhSWxNUiehZkvj9kwSmHt+mBPknf/paLIa4K9fmYzbXXiaLHzs3m2V+uAI GA/os5A9Sm/8f7KQhFfkqDKOGV7yUSA0dFaVu9zpZAABT3jDbPnJ5h/VN0lsQUu34VQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590671; 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=yOCPhI357qczBAr5/58j0TEso4zqDKHgqVeNv7JIscw=; b=cp8MdUeVwuPLo8FTt7pepV8M2f1O99k4nS+6Q9+RXTC+hSSS9lEQwEqIBbyTQOUjHM97 uV+lNk6T0fxNSVo8PdJa/XACj/XhKJnhT9KS//edQiWYoS4rQqGlfQB5WnBbHnLj+q69U bxDjmOJvrByLSRdzWowO0k21OlgiY3+bIkL68vVU+IUGE0far2THbhcZQHU2noxh5B+Lz NeMZT8az5d8+V6SwbQugqcGLhuKuynOWw862CE/MT3OJhExdHbyBm4A43/r0Lv3+yiAzF JMgPRfgznaEjscwdq7EiXCF/lrE8pFCnnsgrON9QlbasZdbII39N5trvL+9b839ZR9g== 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=iJyRctc1; 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 A9560606B21B; Fri, 13 Nov 2026 17:24:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=iJyRctc1 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5675E1F000C4; Fri, 13 Nov 2026 17:24:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590671; bh=yOCPhI357qczBAr5/58j0TEso4zqDKHgqVeNv7JIscw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=iJyRctc1yz0u4/H5ZXT4GRN1WtBWTQUQgh225IiXiF2BOzhGkZ6+//CmV04oGiOEi LY3OQBD/DuVtnZitGrvcKfWHWNoGTarv7PBGGjU8PDV0Ji0B4qJn7z4MSiolv2wVYc RSPpKsmpVLSqR9r4DNYAJ1ZCHjFcRZqBwFVja+nw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hugo Villeneuve , Sasha Levin Subject: [PATCH 6.18 586/686] serial: sc16is7xx: add comments for lock requirements Date: Fri, 13 Nov 2026 10:51:59 -0500 Message-ID: <20261113153841.670202491@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hugo Villeneuve [ Upstream commit 42405cb77fd35b5acc0e5a11d74eef68c2afa484 ] Indicate why lock needs to be asserted when accessing MSR register, as this is not immediately obvious when looking at this register in the device datasheet. Signed-off-by: Hugo Villeneuve Link: https://patch.msgid.link/20251027142957.1032073-15-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 1c41d09dcd07 ("serial: sc16is7xx: declare MCR and IER as volatile registers") Signed-off-by: Sasha Levin --- drivers/tty/serial/sc16is7xx.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 7cf3056b93939..b2d020a0b20d0 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -538,10 +538,10 @@ EXPORT_SYMBOL_GPL(sc16is762_devtype); static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) { switch (reg) { - case SC16IS7XX_RHR_REG: - case SC16IS7XX_IIR_REG: - case SC16IS7XX_LSR_REG: - case SC16IS7XX_MSR_REG: + case SC16IS7XX_RHR_REG: /* Shared address space with THR & DLL */ + case SC16IS7XX_IIR_REG: /* Shared address space with FCR & EFR */ + case SC16IS7XX_LSR_REG: /* Shared address space with XON2 */ + case SC16IS7XX_MSR_REG: /* Shared address space with TCR & XOFF1 */ case SC16IS7XX_SPR_REG: /* Shared address space with TLR & XOFF2 */ case SC16IS7XX_TXLVL_REG: case SC16IS7XX_RXLVL_REG: @@ -785,6 +785,7 @@ static void sc16is7xx_update_mlines(struct sc16is7xx_one *one) unsigned long flags; unsigned int status, changed; + /* Lock required as MSR address is shared with TCR and XOFF1. */ lockdep_assert_held_once(&one->lock); status = sc16is7xx_get_hwmctrl(port); -- 2.53.0