linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: broonie@kernel.org
Cc: gregkh@linuxfoundation.org, rafael@kernel.org,
	ckeepax@opensource.cirrus.com, tanureal@opensource.cirrus.com,
	linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Subject: [PATCH] regmap: sdw: check for invalid multi-register writes config
Date: Tue, 23 May 2023 16:47:47 +0100	[thread overview]
Message-ID: <20230523154747.5429-1-srinivas.kandagatla@linaro.org> (raw)

SoundWire code as it is only supports Bulk register writes and
it does not support multi-register writes.

Any drivers that set can_multi_write and use regmap_multi_reg_write() will
easily endup with programming the hardware incorrectly without any errors.

So, add this check in bus code to be able to validate the drivers config.

Fixes: 522272047dc6 ("regmap: sdw: Remove 8-bit value size restriction")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/base/regmap/regmap-sdw.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c
index 09899ae99fc1..159c0b740b00 100644
--- a/drivers/base/regmap/regmap-sdw.c
+++ b/drivers/base/regmap/regmap-sdw.c
@@ -59,6 +59,10 @@ static int regmap_sdw_config_check(const struct regmap_config *config)
 	if (config->pad_bits != 0)
 		return -ENOTSUPP;
 
+	/* Only bulk writes are supported not multi-register writes */
+	if (config->can_multi_write)
+		return -ENOTSUPP;
+
 	return 0;
 }
 
-- 
2.21.0


             reply	other threads:[~2023-05-23 15:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-23 15:47 Srinivas Kandagatla [this message]
2023-05-23 16:58 ` [PATCH] regmap: sdw: check for invalid multi-register writes config Mark Brown
2023-05-23 17:13   ` Srinivas Kandagatla
2023-05-23 17:25     ` Mark Brown
2023-05-24 11:58 ` Mark Brown

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230523154747.5429-1-srinivas.kandagatla@linaro.org \
    --to=srinivas.kandagatla@linaro.org \
    --cc=alsa-devel@alsa-project.org \
    --cc=broonie@kernel.org \
    --cc=ckeepax@opensource.cirrus.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rafael@kernel.org \
    --cc=tanureal@opensource.cirrus.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).