[PATCH v3 2/4] coresight: ultrasoc-smb: Config SMB buffer before register sink

From: Junhao He
Date: Tue Nov 14 2023 - 08:33:43 EST


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@xxxxxxxxxx>
---
drivers/hwtracing/coresight/ultrasoc-smb.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index 0a0fe9fcc57f..2f2aba90a514 100644
--- 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;
}

--
2.33.0