mailbox: pcc: Reset pcc_chan_count to zero in case of PCC probe failure

[ Upstream commit 6d7d3c2874 ]

Currently, 'pcc_chan_count' is remains set to a non-zero value if PCC
subspaces are parsed successfully but something else fail later during
the initial PCC probing phase. This will result in pcc_mbox_request_channel
trying to access the resources that are not initialised or allocated and
may end up in a system crash.

Reset pcc_chan_count to 0 when the PCC probe fails in order to prevent
the possible issue as described above.

Fixes: ce028702dd ("mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe")
Signed-off-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/mailbox/pcc.c

@@ -743,6 +743,7 @@ static int __init pcc_init(void)
 
 	if (IS_ERR(pcc_pdev)) {
 		pr_debug("Err creating PCC platform bundle\n");
+		pcc_chan_count = 0;
 		return PTR_ERR(pcc_pdev);
 	}