[PATCH 6.18 313/752] mailbox: mchp-ipc-sbi: fix uninitialized symbol and other smatch warnings

Sasha Levin
2026-02-28T17:52:30Z

From: Valentina Fernandez <valentina.fernandezalanis@microchip.com>

[ Upstream commit bc4d17e495cd3b02bcb2e10f575763a5ff31f80b ]

Fix uninitialized symbol 'hartid' warning in mchp_ipc_cluster_aggr_isr()
by introducing a 'found' flag to track whether the IRQ matches any
online hart. If no match is found, return IRQ_NONE.

Also fix other smatch warnings by removing dead code in
mchp_ipc_startup() and by returning -ENODEV in dev_err_probe() if the
Microchip SBI extension is not found.

Fixes below smatch warnings:
drivers/mailbox/mailbox-mchp-ipc-sbi.c:187 mchp_ipc_cluster_aggr_isr() error: uninitialized symbol 'hartid'.
drivers/mailbox/mailbox-mchp-ipc-sbi.c:324 mchp_ipc_startup() warn: ignoring unreachable code.
drivers/mailbox/mailbox-mchp-ipc-sbi.c:422 mchp_ipc_probe() warn: passing zero to 'dev_err_probe'

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202512171533.CDLdScMY-lkp@intel.com/
Signed-off-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mailbox/mailbox-mchp-ipc-sbi.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/mailbox/mailbox-mchp-ipc-sbi.c b/drivers/mailbox/mailbox-mchp-ipc-sbi.c
index d444491a584e8..b87bf2fb4b9b9 100644
--- a/drivers/mailbox/mailbox-mchp-ipc-sbi.c
+++ b/drivers/mailbox/mailbox-mchp-ipc-sbi.c
@@ -174,17 +174,21 @@ static irqreturn_t mchp_ipc_cluster_aggr_isr(int irq, void *data)
struct mchp_ipc_msg ipc_msg;
struct mchp_ipc_status status_msg;
int ret;
- unsigned long hartid;
u32 i, chan_index, chan_id;
+ bool found = false;

/* Find out the hart that originated the irq */
for_each_online_cpu(i) {
- hartid = cpuid_to_hartid_map(i);
- if (irq == ipc->cluster_cfg[i].irq)
+ if (irq == ipc->cluster_cfg[i].irq) {
+ found = true;
break;
+ }
}

- status_msg.cluster = hartid;
+ if (unlikely(!found))
+ return IRQ_NONE;
+
+ status_msg.cluster = cpuid_to_hartid_map(i);
memcpy(ipc->cluster_cfg[i].buf_base, &status_msg, sizeof(struct mchp_ipc_status));

ret = mchp_ipc_sbi_send(SBI_EXT_IPC_STATUS, ipc->cluster_cfg[i].buf_base_addr);
@@ -321,13 +325,6 @@ static int mchp_ipc_startup(struct mbox_chan *chan)
goto fail_free_buf_msg_rx;
}

- if (ret) {
- dev_err(ipc->dev, "failed to register interrupt(s)\n");
- goto fail_free_buf_msg_rx;
- }
-
- return ret;
-
fail_free_buf_msg_rx:
kfree(chan_info->msg_buf_rx);
fail_free_buf_msg_tx:
@@ -419,7 +416,7 @@ static int mchp_ipc_probe(struct platform_device *pdev)

ret = sbi_probe_extension(SBI_EXT_MICROCHIP_TECHNOLOGY);
if (ret <= 0)
- return dev_err_probe(dev, ret, "Microchip SBI extension not detected\n");
+ return dev_err_probe(dev, -ENODEV, "Microchip SBI extension not detected\n");

ipc = devm_kzalloc(dev, sizeof(*ipc), GFP_KERNEL);
if (!ipc)
--
2.51.0