6.4-stable review patch. If anyone has any objections, please let me know.
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From: Frank Li Frank.Li@nxp.com
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@vger.kernel.org Fixes: dd3c52846d59 ("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 --- 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 @@ -782,6 +782,10 @@ 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 @@ -1251,11 +1255,17 @@ 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,