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 6BD8912880A; Tue, 14 May 2024 10:53:53 +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=1715684033; cv=none; b=nj7P0iLMoncjswJLGNOh5bT0J5zJ5vcgqf4cuIIEgEgRdQdMgFlulHW412E74JHLxjcB4Y2O0NGhfbxiPA+9HHTUPqiW6x2B1PovgziaB5xBqCZEwLzQM3LE1SP9wMIj8oJ0urzBdirdj8jLfVxfGvG8h20fPHnQjE+fAfAR8Cs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715684033; c=relaxed/simple; bh=TBKGuXcafzvLg7tjDHbPg5q0D6oS3JI7sxFuDct3UuA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gSCa/c/2sKPxW0Dz/hr9D0XqamKW5LyMBGKr/bxIRz3Xmhjd1iW+n5yAwQ0RbFYCKwaxMgxAbY3V+BlBgS7zx97gqaVPoUwpAAoCDF7tX9dLrlAFLdAdwQi1YswiE+ucUvCeiEtxLvRTfZxUCvWXyk3zhcoD/4Z5Xqmu+eYp/Oc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PCy7vtMY; 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="PCy7vtMY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15AEBC2BD10; Tue, 14 May 2024 10:53:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1715684033; bh=TBKGuXcafzvLg7tjDHbPg5q0D6oS3JI7sxFuDct3UuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PCy7vtMY5OQLQ4LEZdY0mGQpMosvVZFqPtsC5l8wq2GlJLutlUS+R7yo7GxAAMLxF FFUoA+pIrbb8JG490xfZ4F6jhXjNXgvbENkCuDjXU9f/YcN3xVg1Ed+r9LTS/zmSDG G8zVCL28ZlpVv+pkxoA7z7U3qh98HbWNFRcsVs5I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lakshmi Yadlapati , Eddie James , Guenter Roeck Subject: [PATCH 6.8 310/336] hwmon: (pmbus/ucd9000) Increase delay from 250 to 500us Date: Tue, 14 May 2024 12:18:34 +0200 Message-ID: <20240514101050.321845612@linuxfoundation.org> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240514101038.595152603@linuxfoundation.org> References: <20240514101038.595152603@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: Lakshmi Yadlapati commit 26e8383b116d0dbe74e28f86646563ab46d66d83 upstream. Following the failure observed with a delay of 250us, experiments were conducted with various delays. It was found that a delay of 350us effectively mitigated the issue. To provide a more optimal solution while still allowing a margin for stability, the delay is being adjusted to 500us. Signed-off-by: Lakshmi Yadlapati Link: https://lore.kernel.org/r/20240507194603.1305750-1-lakshmiy@us.ibm.com Fixes: 8d655e6523764 ("hwmon: (ucd90320) Add minimum delay between bus accesses") Reviewed-by: Eddie James Cc: stable@vger.kernel.org Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hwmon/pmbus/ucd9000.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/hwmon/pmbus/ucd9000.c +++ b/drivers/hwmon/pmbus/ucd9000.c @@ -80,11 +80,11 @@ struct ucd9000_debugfs_entry { * It has been observed that the UCD90320 randomly fails register access when * doing another access right on the back of a register write. To mitigate this * make sure that there is a minimum delay between a write access and the - * following access. The 250us is based on experimental data. At a delay of - * 200us the issue seems to go away. Add a bit of extra margin to allow for + * following access. The 500 is based on experimental data. At a delay of + * 350us the issue seems to go away. Add a bit of extra margin to allow for * system to system differences. */ -#define UCD90320_WAIT_DELAY_US 250 +#define UCD90320_WAIT_DELAY_US 500 static inline void ucd90320_wait(const struct ucd9000_data *data) {