[PATCH v2 1/3] i3c: Add comment for -EAGAIN in i3c_device_do_priv_xfers()

From: Frank Li
Date: Mon May 06 2024 - 12:40:40 EST


In accordance with I3C spec ver 1.1.1 09-Jun-2021, section: 5.1.2.2.3, if
a target requests hot join (HJ), In-Band Interrupt (IBI), or controller
role request (CRR) during the emission of an I3C address in
i3c_device_do_priv_xfers(), the target may win bus arbitration. In such
cases, it is imperative to notify the I3C client driver and retry
i3c_device_do_priv_xfers() after some delay.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---

Notes:
Change from v1 to v2
- new patch

drivers/i3c/device.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c
index 1a6a8703dbc3a..b04a55a1337d4 100644
--- a/drivers/i3c/device.c
+++ b/drivers/i3c/device.c
@@ -27,6 +27,10 @@
* This function can sleep and thus cannot be called in atomic context.
*
* Return: 0 in case of success, a negative error core otherwise.
+ * -EAGAIN: controller lost address arbitration. Target
+ * (IBI, HJ or controller role request) win the bus. Client
+ * driver need resend this 'xfers' some time later.
+ * See I3C spec ver 1.1.1 09-Jun-2021. Section: 5.1.2.2.3.
*/
int i3c_device_do_priv_xfers(struct i3c_device *dev,
struct i3c_priv_xfer *xfers,
--
2.34.1