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i3c: master: svc: fix probe failure when no i3c device exist 

commit 6e13d6528b 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@vger.kernel.org
Fixes: dd3c52846d ("i3c: master: svc: Add Silvaco I3C master driver")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20230831141324.2841525-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Frank Li 2023-08-31 10:13:24 -04:00 committed by Greg Kroah-Hartman
parent 9b445804b1
commit 6188593689
1 changed files with 12 additions and 2 deletions
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14
drivers/i3c/master/svc-i3c-master.c
View File

@ -782,6 +782,10 @@ static int svc_i3c_master_do_daa_locked(struct svc_i3c_master *master,
*/
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
@ -1251,11 +1255,17 @@ static int svc_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
{
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,