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authorAdrian Ng Ho Yin <adrianhoyin.ng@altera.com>2025-12-12 17:02:55 +0800
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2026-01-13 18:26:47 +0100
commitb58f47eb392680d4c6626c8b3b1fcf6412a0a02c (patch)
treec8779ec30cc692300ece3f63bb52555f79380651 /Documentation
parent8f0b4cce4481fb22653697cced8d0d04027cb1e8 (diff)
i3c: add sysfs entry and attribute for Device NACK Retry count
Document sysfs attribute dev_nack_retry_cnt that controls the number of automatic retries performed by the I3C controller when a target device returns a NACK Add a `dev_nack_retry_count` sysfs attribute to allow reading and updating the device NACK retry count. A new `dev_nack_retry_count` field and an optional `set_dev_nack_retry()` callback are added to i3c_master_controller. The attribute is created only when the callback is implemented. Updates are applied under the I3C bus maintenance lock to ensure safe hardware reconfiguration. Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng@altera.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/3c4b5082bde64024fc383c44bebeef89ad3c7ed3.1765529948.git.adrianhoyin.ng@altera.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-i3c11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-i3c b/Documentation/ABI/testing/sysfs-bus-i3c
index c812ab180ff4..c1e048957a01 100644
--- a/Documentation/ABI/testing/sysfs-bus-i3c
+++ b/Documentation/ABI/testing/sysfs-bus-i3c
@@ -161,3 +161,14 @@ Contact: linux-i3c@vger.kernel.org
Description:
These directories are just symbolic links to
/sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>.
+
+What: /sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dev_nack_retry_count
+KernelVersion: 6.18
+Contact: linux-i3c@vger.kernel.org
+Description:
+ Expose the dev_nak_retry_count which controls the number of
+ automatic retries that will be performed by the controller when
+ the target device returns a NACK response. A value of 0 disables
+ the automatic retries. Exist only when I3C constroller supports
+ this retry on nack feature.
+