commit 38baed9b86 upstream.
In an In-Band Interrupt (IBI) handle, the code logic is as follows:
1: writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI | SVC_I3C_MCTRL_IBIRESP_AUTO,
master->regs + SVC_I3C_MCTRL);
2: ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val,
SVC_I3C_MSTATUS_IBIWON(val), 0, 1000);
...
3: ibitype = SVC_I3C_MSTATUS_IBITYPE(status);
ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status);
SVC_I3C_MSTATUS_IBIWON may be set before step 1. Thus, step 2 will return
immediately, and the I3C controller has not sent out the 9th SCL yet.
Consequently, ibitype and ibiaddr are 0, resulting in an unknown IBI type
occurrence and missing call I3C client driver's IBI handler.
A typical case is that SVC_I3C_MSTATUS_IBIWON is set when an IBI occurs
during the controller send start frame in svc_i3c_master_xfer().
Clear SVC_I3C_MSTATUS_IBIWON before issue SVC_I3C_MCTRL_REQUEST_AUTO_IBI
to fix this issue.
Cc: stable@vger.kernel.org
Fixes: 5e5e3c92e7 ("i3c: master: svc: fix wrong data return when IBI happen during start frame")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240506164009.21375-3-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
aed55acbb9