From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99D5D1A2FA6; Thu, 6 Jun 2024 14:13:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683212; cv=none; b=UyK5PcRSy0ItBhweSNJQC7oyKcE+UKeKyKTuLRCz8+/A+EfFo3/DL8Bq31W3w3FXai4Wala/5vxd1MrwfjZxi2ffMYGKXhanLeKp5+TUsXbeRWQdZ46xZX8eu1YdTz2JzsJfvX/mCSj4DIeQpsGg0dfYIJw5Fvc+uS/4QM+14Mg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683212; c=relaxed/simple; bh=nHyoxvrxT4+OJclaBuG2XvvEx/56Uk6WUDKkfw4nzeI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=REYI4sRnBO2EcJ/Ru4CoDcv3Du4hwSnOc/6ixWjDXEK/xyUisUa6XUl/dn6Pb0Cc9M0n4rpEHrCq12wMw9QeJ5RTOF0FG1J8AaX48Kx5FDRUgJJKdnxKA2kDbP4I4iGet2XcBvK3rBT252vDqhDewdThk8QV54rDA124B3yoRjA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YhUA9TAJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="YhUA9TAJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75B3BC2BD10; Thu, 6 Jun 2024 14:13:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1717683212; bh=nHyoxvrxT4+OJclaBuG2XvvEx/56Uk6WUDKkfw4nzeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YhUA9TAJaLdkBSx8mJ87NL+huVMlafBte907WW1lKOshKy/uSAiEnbyJsaVlDyU0C jV5rMJSusXbR7cr6THT10u+t6rlW53L1hxrMpb1/60fsIFSDafKmpPffJKMwDVAwhV ZFNxYdes4nLx0y1/7aCICMLLF31KbDtJ6gNZtM5o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Manivannan Sadhasivam , Bart Van Assche , Can Guo , Andrew Halaney , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.6 155/744] scsi: ufs: core: Perform read back after writing UTP_TASK_REQ_LIST_BASE_H Date: Thu, 6 Jun 2024 15:57:07 +0200 Message-ID: <20240606131737.390256333@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240606131732.440653204@linuxfoundation.org> References: <20240606131732.440653204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Halaney [ Upstream commit 408e28086f1c7a6423efc79926a43d7001902fae ] Currently, the UTP_TASK_REQ_LIST_BASE_L/UTP_TASK_REQ_LIST_BASE_H regs are written to and then completed with an mb(). mb() ensures that the write completes, but completion doesn't mean that it isn't stored in a buffer somewhere. The recommendation for ensuring these bits have taken effect on the device is to perform a read back to force it to make it all the way to the device. This is documented in device-io.rst and a talk by Will Deacon on this can be seen over here: https://youtu.be/i6DayghhA8Q?si=MiyxB5cKJXSaoc01&t=1678 Let's do that to ensure the bits hit the device. Because the mb()'s purpose wasn't to add extra ordering (on top of the ordering guaranteed by writel()/readl()), it can safely be removed. Fixes: 88441a8d355d ("scsi: ufs: core: Add hibernation callbacks") Reviewed-by: Manivannan Sadhasivam Reviewed-by: Bart Van Assche Reviewed-by: Can Guo Signed-off-by: Andrew Halaney Link: https://lore.kernel.org/r/20240329-ufs-reset-ensure-effect-before-delay-v5-7-181252004586@redhat.com Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/ufs/core/ufshcd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 344806330be16..cd1b9db8543dc 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -10152,7 +10152,7 @@ int ufshcd_system_restore(struct device *dev) * are updated with the latest queue addresses. Only after * updating these addresses, we can queue the new commands. */ - mb(); + ufshcd_readl(hba, REG_UTP_TASK_REQ_LIST_BASE_H); /* Resuming from hibernate, assume that link was OFF */ ufshcd_set_link_off(hba); -- 2.43.0