5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Frank Li <Frank.Li@xxxxxxx>
commit 6e13d6528be2f7e801af63c8153b87293f25d736 upstream.
I3C masters are expected to support hot-join. This means at initialization
time we might not yet discover any device and this should not be treated
as a fatal error.
During the DAA procedure which happens at probe time, if no device has
joined, all CCC will be NACKed (from a bus perspective). This leads to an
early return with an error code which fails the probe of the master.
Let's avoid this by just telling the core through an I3C_ERROR_M2
return command code that no device was discovered, which is a valid
situation. This way the master will no longer bail out and fail to probe
for a wrong reason.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
Acked-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230831141324.2841525-1-Frank.Li@xxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i3c/master/svc-i3c-master.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -723,6 +723,10 @@ static int svc_i3c_master_do_daa_locked(
*/
break;
} else if (SVC_I3C_MSTATUS_NACKED(reg)) {
+ /* No I3C devices attached */
+ if (dev_nb == 0)
+ break;
+
/*
* A slave device nacked the address, this is
* allowed only once, DAA will be stopped and
@@ -1152,11 +1156,17 @@ static int svc_i3c_master_send_ccc_cmd(s
{
struct svc_i3c_master *master = to_svc_i3c_master(m);
bool broadcast = cmd->id < 0x80;
+ int ret;
if (broadcast)
- return svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);
+ ret = svc_i3c_master_send_bdcast_ccc_cmd(master, cmd);
else
- return svc_i3c_master_send_direct_ccc_cmd(master, cmd);
+ ret = svc_i3c_master_send_direct_ccc_cmd(master, cmd);
+
+ if (ret)
+ cmd->err = I3C_ERROR_M2;
+
+ return ret;
}
static int svc_i3c_master_priv_xfers(struct i3c_dev_desc *dev,
