coresight: ultrasoc-smb: Config SMB buffer before register sink

[ Upstream commit 830a7f54db102c889a3fe1c0a225f369ac05f07f ]

The SMB dirver register the enable/disable sysfs interface in function
smb_register_sink(), however the buffer depends on the following
configuration to work well. So it'll be possible for user to access an
unreset one.

Move the config buffer operation to before register_sink().
Ignore the return value, if smb_config_inport() fails. That will
cause the hardwares disable trace path to fail, should not affect
SMB driver remove. So we make smb_remove() return success,

Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer driver")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231114133346.30489-3-hejunhao3@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index 0a0fe9fcc57f9d211757d7de784dbdf86b8ed97a..2f2aba90a5148aff16f4062e21de4fa64cee0abe 100644 (file)
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -583,37 +583,32 @@ static int smb_probe(struct platform_device *pdev)
                return ret;
        }
 
+       ret = smb_config_inport(dev, true);
+       if (ret)
+               return ret;
+
+       platform_set_drvdata(pdev, drvdata);
        spin_lock_init(&drvdata->spinlock);
        drvdata->pid = -1;
 
        ret = smb_register_sink(pdev, drvdata);
        if (ret) {
+               smb_config_inport(&pdev->dev, false);
                dev_err(dev, "Failed to register SMB sink\n");
                return ret;
        }
 
-       ret = smb_config_inport(dev, true);
-       if (ret) {
-               smb_unregister_sink(drvdata);
-               return ret;
-       }
-
-       platform_set_drvdata(pdev, drvdata);
-
        return 0;
 }
 
 static int smb_remove(struct platform_device *pdev)
 {
        struct smb_drv_data *drvdata = platform_get_drvdata(pdev);
-       int ret;
-
-       ret = smb_config_inport(&pdev->dev, false);
-       if (ret)
-               return ret;
 
        smb_unregister_sink(drvdata);
 
+       smb_config_inport(&pdev->dev, false);
+
        return 0;
 }