[PATCH v2 0/3] i3c: dw-i3c: Enable support for dw-i3c controller NACK retry sysfs and DAT restore fix

adrianhoyin.ng
2025-11-21T06:24:24Z

This patch series adds a controller-wide sysfs attribute
dev_nack_retry_count for the DesignWare I3C controller, allowing runtime
control of the automatic retry mechanism when a device NACKs. Some I3C
slave devices may temporarily be busy and unable to respond immediately;
automatic retries improve robustness in such cases. Writes are clamped to
the hardware maximum of 3, and the value is applied to all active DAT
entries.

The series also fixes dw_i3c_master_restore_addrs() to preserve existing
DAT entry bits, preventing overwrites during runtime PM resume.

---
changelog:
v1->v2
* Drop dev_nack_retry_cnt binding and device tree changes.
* Update commit message for better clarity.
* Update to use controller wide sysfs attribute that configures
dev_nack_retry_cnt during runtime.

v1 patch link:
https://lore.kernel.org/all/cover.1762245890.git.adrianhoyin.ng@altera.com/
---

Adrian Ng Ho Yin (3):
i3c: add sysfs entry for Device NACK Retry count
i3c: dw: Add sysfs support for Device NACK Retry count
i3c: dw: Preserve DAT entry bits when restoring addresses

Documentation/ABI/testing/sysfs-bus-i3c | 11 ++++
drivers/i3c/master/dw-i3c-master.c | 70 ++++++++++++++++++++++++-
drivers/i3c/master/dw-i3c-master.h | 1 +
3 files changed, 80 insertions(+), 2 deletions(-)

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2.49.GIT