Re: [PATCH v2] mediatek/mt7601u: add debugfs exit function

z  [off-list ref] writes:

At 2022-04-23 03:47:04, "Jakub Kicinski" [off-list ref] wrote:

quoted

On Fri, 22 Apr 2022 01:08:54 -0700 Bernard Zhao wrote:

quoted

When mt7601u loaded, there are two cases:
First when mt7601u is loaded, in function mt7601u_probe, if
function mt7601u_probe run into error lable err_hw,
mt7601u_cleanup didn`t cleanup the debugfs node.
Second when the module disconnect, in function mt7601u_disconnect,
mt7601u_cleanup didn`t cleanup the debugfs node.
This patch add debugfs exit function and try to cleanup debugfs
node when mt7601u loaded fail or unloaded.

Signed-off-by: Bernard Zhao <redacted>

Ah, missed that there was a v2. My point stands, wiphy debugfs dir
should do the cleanup.

Do you encounter problems in practice or are you sending this patches
based on reading / static analysis of the code only.

Hi Jakub Kicinski:

The issue here is found by reading code.
I read the drivers/net/wireless code and found that many modules are
not cleanup the debugfs.
I sorted out the modules that were not cleaned up the debugfs:
./ti/wl18xx
./ti/wl12xx
./intel/iwlwifi
./intel/iwlwifi
./mediatek/mt76
I am not sure whether this part is welcome to kernel so I submitted a patch.
If you have any suggestions, welcome to put forward for discussion, thank you！

Jakub is saying that wiphy_unregister() recursively removes the debugfs
directories:

	/*
	 * First remove the hardware from everywhere, this makes
	 * it impossible to find from userspace.
	 */
	debugfs_remove_recursive(rdev->wiphy.debugfsdir);

So AFAICS there is no bug. But if you are testing this on a real
hardware and something is wrong, please provide more info.

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