From 0d25965082013a3743972ca1887380b66de47dd3 Mon Sep 17 00:00:00 2001 From: Frank Li Date: Mon, 6 May 2024 12:40:07 -0400 Subject: [PATCH] i3c: Add comment for -EAGAIN in i3c_device_do_priv_xfers() 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 Reviewed-by: Miquel Raynal Link: https://lore.kernel.org/r/20240506164009.21375-1-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni --- drivers/i3c/device.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/i3c/device.c b/drivers/i3c/device.c index 1a6a8703dbc3..e80e48756914 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 needs to resend the '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,