[PATCH v2] i3c: don't fail if GETHDRCAP is unsupported

From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-renesas-soc@vger.kernel.org
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Frank Li <Frank.Li@nxp.com>,
	linux-i3c@lists.infradead.org
Subject: [PATCH v2] i3c: don't fail if GETHDRCAP is unsupported
Date: Fri,  4 Jul 2025 22:44:32 +0200	[thread overview]
Message-ID: <20250704204524.6124-1-wsa+renesas@sang-engineering.com> (raw)

'I3C_BCR_HDR_CAP' is still spec v1.0 and has been renamed to 'advanced
capabilities' in v1.1 onwards. The ST pressure sensor LPS22DF does not
have HDR, but has the 'advanced cap' bit set. The core still wants to
get additional information using the CCC 'GETHDRCAP' (or GETCAPS in v1.1
onwards). Not all controllers support this CCC and will notify the upper
layers about it. For instantiating the device, we can ignore this
unsupported CCC as standard communication will work. Without this patch,
the device will not be instantiated at all.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Changes since v1:
* updated commit message

Please note that Joshua Yeong was also in favor of this patch. Sadly, he
did not send an official Acked-by yet.

 drivers/i3c/master.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index fd81871609d9..e53c69d24873 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1439,7 +1439,7 @@ static int i3c_master_retrieve_dev_info(struct i3c_dev_desc *dev)
 
 	if (dev->info.bcr & I3C_BCR_HDR_CAP) {
 		ret = i3c_master_gethdrcap_locked(master, &dev->info);
-		if (ret)
+		if (ret && ret != -ENOTSUPP)
 			return ret;
 	}
 
-- 
2.47.2


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