[214/272] hostap_cs: fix sleeping function called from invalid context

Greg KH
2011-02-16T00:24:28Z

From: Stanislaw Gruszka <sgruszka@redhat.com>

commit 4e5518ca53be29c1ec3c00089c97bef36bfed515 upstream.

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
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/net/wireless/hostap/hostap_cs.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)

--- a/drivers/net/wireless/hostap/hostap_cs.c
+++ b/drivers/net/wireless/hostap/hostap_cs.c
@@ -518,22 +518,21 @@ static int prism2_config(struct pcmcia_d
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;
@@ -546,8 +545,6 @@ static int prism2_config(struct pcmcia_d

return ret;

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