Emmanuel Grumbach <egrumbach@xxxxxxxxx> writes:
> From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
>
> None of the devices supported by iwldvm have support for
> shadow registers. This means that we wake the NIC
> when we increment the write pointer on Tx ring.
> This happened even before my bad commit mentionned below.
> Since my commit below, we wake up the NIC when we put a
> host command on the ring regardless of shadow register
> support. This means that in iwldvm (when the NIC doesn't
> support shadow register), we wake up the NIC twice:
>
> pcie_enqueue_hcmd:
> wake up the NIC
> iwl_pcie_txq_inc_wr_ptr:
> wake up the NIC - no shadow reg support
>
> Since waking up the NIC means that we need to acquire a
> spinlock, this obviously leads to a recursive spinlock
> and hence a freeze.
>
> Fixes: b9439491055a ("iwlwifi: pcie: keep the NIC awake when commands are in flight")
> Reported-by: Janusz Dziedzic <janusz.dziedzic@xxxxxxxxx>
> Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Ah, this is why my laptop was hanging during boot with latest
wireless-testing? Thanks for fixing this.
FWIW:
Tested-by: Kalle Valo <kvalo@xxxxxxxxxx>
--
Kalle Valo
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