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 7459FD518; Mon, 27 May 2024 19:04:03 +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=1716836643; cv=none; b=ZK+A06VbGeswOF3tIWJ/HWZ9lSDfe24seD/10TH7a28+dAtBrsVm9UYy/3VGRUtIp+P9WjNmiPdqLbWPlJncJoBVjS6X+xyXGbYbaRHvfXZyA218L5HVCKdK1HxMJ3uzs9YFDsul0q/PX6RyAo5vWDDqju251jcntig5U/UlY8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716836643; c=relaxed/simple; bh=bwd8lLGc+kom/w9uH97WHMpX3OSUAAA4Yahjco8RabQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jlJzgaL7Kv4Hwd3IKsKDMDaP8eHg5Xz1/ou/ZNJF1KSvktYycKgafMuraBtJpy2plS3hFcFscOlzZjFZS2pRg9dq1f8tKNDnTu38I9Xugluh5zDeZwILJi+oI97q2mrK+OfdCW1PTySJ3a78DHQnK3HeMZfjC4Mm0DtbXulJI3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=062NiORq; 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="062NiORq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AF57C2BBFC; Mon, 27 May 2024 19:04:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716836643; bh=bwd8lLGc+kom/w9uH97WHMpX3OSUAAA4Yahjco8RabQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=062NiORqNi6T12ZoHoeoml/UoQ+9646OInA8HOqJpaKzGtxcVLC0ttiy1MTVcf0PJ /b6OzJoi7UlROJmG9+3fPh6jI4SrRdbVZU5tWV36WcBmaWqfGY1ZJLTZ3MBNa0UhBv MGvyowV5+YzWel35KZAuANMdfx10dbHZw0w+0cJM= 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 6.9 132/427] scsi: ufs: core: Perform read back after disabling interrupts Date: Mon, 27 May 2024 20:52:59 +0200 Message-ID: <20240527185614.215485063@linuxfoundation.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240527185601.713589927@linuxfoundation.org> References: <20240527185601.713589927@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 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Halaney [ Upstream commit e4a628877119bd40164a651d20321247b6f94a8b ] Currently, interrupts are cleared and disabled prior to registering the interrupt. An mb() is used to complete the clear/disable writes before the interrupt is registered. 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 these 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: 199ef13cac7d ("scsi: ufs: avoid spurious UFS host controller interrupts") 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-v5-8-181252004586@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 1352f11c94bb6..5ade57c5a6f4f 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -10621,7 +10621,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) * Make sure that UFS interrupts are disabled and any pending interrupt * status is cleared before registering UFS interrupt handler. */ - mb(); + ufshcd_readl(hba, REG_INTERRUPT_ENABLE); /* IRQ registration */ err = devm_request_irq(dev, irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba); -- 2.43.0