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hostap_cs: fix sleeping function called from invalid context
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pcmcia_request_irq() and pcmcia_enable_device() are intended
to be called from process context (first function allocate memory
with GFP_KERNEL, second take a mutex). We can not take spin lock
and call them.

It's safe to move spin lock after pcmcia_enable_device() as we
still hold off IRQ until dev->base_addr is 0 and driver will
not proceed with interrupts when is not ready.

Patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=643758

Reported-and-tested-by: rbugz@biobind.com
Cc: stable@kernel.org  # 2.6.34+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Stanislaw Gruszka authored and John W. Linville committed Jan 10, 2011
1 parent 3c4a8cc commit 4e5518c
Showing 1 changed file with 6 additions and 9 deletions.
15 changes: 6 additions & 9 deletions drivers/net/wireless/hostap/hostap_cs.c
Original file line number Diff line number Diff line change
Expand Up @@ -518,22 +518,21 @@ static int prism2_config(struct pcmcia_device *link)
hw_priv->link = link;

/*
* Make sure the IRQ handler cannot proceed until at least
* dev->base_addr is initialized.
* We enable IRQ here, but IRQ handler will not proceed
* until dev->base_addr is set below. This protect us from
* receive interrupts when driver is not initialized.
*/
spin_lock_irqsave(&local->irq_init_lock, flags);

ret = pcmcia_request_irq(link, prism2_interrupt);
if (ret)
goto failed_unlock;
goto failed;

ret = pcmcia_enable_device(link);
if (ret)
goto failed_unlock;
goto failed;

spin_lock_irqsave(&local->irq_init_lock, flags);
dev->irq = link->irq;
dev->base_addr = link->resource[0]->start;

spin_unlock_irqrestore(&local->irq_init_lock, flags);

local->shutdown = 0;
Expand All @@ -546,8 +545,6 @@ static int prism2_config(struct pcmcia_device *link)

return ret;

failed_unlock:
spin_unlock_irqrestore(&local->irq_init_lock, flags);
failed:
kfree(hw_priv);
prism2_release((u_long)link);
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