[PATCH] soc: xilinx: Fix a memory leak in zynqmp_pm_remove()

From: Christophe JAILLET
Date: Mon May 29 2023 - 03:53:34 EST

'rx_chan' is known to be NULL here.
Reverse the logic to free the mbox if it has been allocated.

Fixes: ffdbae28d9d1 ("drivers: soc: xilinx: Use mailbox IPI callback")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
'rx_chan' may be NULL, but mbox_free_channel() handles it.
Maybe it is more informative to keep a (useless) "if (rx_chan)" to tell
that it may not be allocated.

On my machine, compilation fails with gcc (Ubuntu 12.1.0-2ubuntu1~22.04):

CC drivers/soc/xilinx/zynqmp_power.o
drivers/soc/xilinx/zynqmp_power.c: In function ‘zynqmp_pm_probe’:
drivers/soc/xilinx/zynqmp_power.c:193:12: error: ‘pm_api_version’ is used uninitialized [-Werror=uninitialized]
193 | if (pm_api_version < ZYNQMP_PM_VERSION)
| ^
drivers/soc/xilinx/zynqmp_power.c:187:13: note: ‘pm_api_version’ was declared here
187 | u32 pm_api_version;
| ^~~~~~~~~~~~~~
cc1: all warnings being treated as errors

I think that this warning is bogus and gcc is wrong.

But I don't know what to do with it :/
Anyway, it is un-realated to this patch.
drivers/soc/xilinx/zynqmp_power.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/soc/xilinx/zynqmp_power.c b/drivers/soc/xilinx/zynqmp_power.c
index 641dcc958911..62a7f6af9544 100644
--- a/drivers/soc/xilinx/zynqmp_power.c
+++ b/drivers/soc/xilinx/zynqmp_power.c
@@ -280,8 +280,7 @@ static int zynqmp_pm_remove(struct platform_device *pdev)
if (event_registered)
xlnx_unregister_event(PM_INIT_SUSPEND_CB, 0, 0, suspend_event_callback, NULL);

- if (!rx_chan)
- mbox_free_channel(rx_chan);
+ mbox_free_channel(rx_chan);

return 0;