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 EF108168C4; Mon, 27 May 2024 19:25:34 +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=1716837935; cv=none; b=npBey8+D90AMaLhfOiCZMj5uR3zXgxtoT1TUvJvwFXdAXMOXlORaIGNHqLnRGC+cc2Fjc7WhwUmxXJoM9CqaCK5qeKEiBtXhtarasbWLAkRL5D2VVdqZ8KUQKeZih5Y37TK4YBpJ8z3Ztys8ri8Z3qhCRbtC9VKBrz/54HOQiGU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716837935; c=relaxed/simple; bh=ZMeoAdKCgbuUj57Cdqv0OASMVRDSKC7jK+X72f+vXHg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aPm0YxjEWyQqBK45FXUf0cK+O7WZA4DS2AWDoeGUA6ipm0p8OfZPEsZTj4eoieX8/m/mzMuDemUqnifynFJNEXsXAi/fOVgK1z+ZZ5zshF9/Trogasec4TI1t91M/fsXOA5qYw/eAwFyGR949OaFFfCJioCs/ocp4iXayUgK+Lc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0OGGqaip; 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="0OGGqaip" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84E97C2BBFC; Mon, 27 May 2024 19:25:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1716837934; bh=ZMeoAdKCgbuUj57Cdqv0OASMVRDSKC7jK+X72f+vXHg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0OGGqaipqgGGq/2Z1pidzqkv9DWrn+HpzSieYuC0ig3bN/BNzmXfgKOSigPcQgwUi Rtjzj5rwwiH6d5ZifTW3iYKMMyfS3Au8xu0XU0lQAVrqNK+FaXJ+LOYWpskMN0StgW N+RMWprMrsqUkDyOEcnaQfQp9tyececqCYysZOYY= 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 6.8 201/493] scsi: ufs: core: Perform read back after disabling interrupts Date: Mon, 27 May 2024 20:53:23 +0200 Message-ID: <20240527185636.902481630@linuxfoundation.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240527185626.546110716@linuxfoundation.org> References: <20240527185626.546110716@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.8-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 16dc63632e720..33068bbfa7a31 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -10570,7 +10570,7 @@ 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