Linux wireless drivers development
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From: Zhao Li <enderaoelyther@gmail.com>
To: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com>,
	linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] wifi: iwlegacy: unregister the LED if 3945 hardware registration fails
Date: Thu, 29 Oct 2026 17:43:37 +0800	[thread overview]
Message-ID: <20261029094336.19250-2-enderaoelyther@gmail.com> (raw)
In-Reply-To: <20261029081955.GA10212@wp.pl>

Hi Stanislaw,

On Thu, Oct 29, 2026 at 09:19:55AM +0100, Stanislaw Gruszka wrote:
> On Wed, Oct 28, 2026 at 10:23:28PM +0800, Zhao Li wrote:
> > il3945_setup_mac() registers the LED before the mac80211 hardware, but
> > its registration error path does not call il_leds_exit(). The analogous
> > 4965 failure releases the driver and reaches its existing remove cleanup.
>
> Could you explain exacly how this is fixed in 4965?
> I do not see this in the code.

There is no il_leds_exit() in the 4965 error path itself. The caller
handles it: il4965_mac_setup_register() runs from the firmware callback,
and a failure there unbinds the driver.

  il4965_ucode_callback()
    il4965_mac_setup_register()   /* il_leds_init(), register_hw fails */
    goto out_unbind
      complete(&il->_4965.firmware_loading_complete)
      device_release_driver(&il->pci_dev->dev)
        il4965_pci_remove()
          il_leds_exit(il)
          ...
          ieee80211_free_hw(il->hw)

il4965_pci_probe() returns success after submitting the asynchronous
firmware request. If the callback reaches device_release_driver()
before probe finishes, the device lock serializes unbind with probe.
The callback completes firmware_loading_complete before unbinding,
and il4965_pci_remove() unregisters the LED regardless of
mac80211_registered.

3945 calls il3945_setup_mac() directly from il3945_pci_probe(), and the
probe error labels never call il_leds_exit(). ieee80211_free_hw() then
frees the il_priv that embeds il->led while the LED is still on
leds_list, so the next led_trigger_register() takes the trigger_lock of
a freed LED.

That should have been in the changelog. I'll send a v2 that spells out
the 4965 path; the code change stays the same.

Thanks,
Zhao

      reply	other threads:[~2026-10-29  9:44 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-28 14:23 [PATCH] wifi: iwlegacy: unregister the LED if 3945 hardware registration fails Zhao Li
2026-10-29  8:19 ` Stanislaw Gruszka
2026-10-29  9:43   ` Zhao Li [this message]

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