hostap_cs: fix sleeping function called from invalid context

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: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/net/wireless/hostap/hostap_cs.c b/drivers/net/wireless/hostap/hostap_cs.c
index f33e18ecac6ac06aa741c38c716b3e8db80c0ead..e436acab121c8328359569849508bc5d6d6364c1 100644 (file)
--- a/drivers/net/wireless/hostap/hostap_cs.c
+++ b/drivers/net/wireless/hostap/hostap_cs.c
@@ -638,11 +638,10 @@ static int prism2_config(struct pcmcia_device *link)
        link->dev_node = &hw_priv->node;
 
        /*
-        * 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);
-
        /*
         * Allocate an interrupt line.  Note that this does not assign a
         * handler to the interrupt, unless the 'Handler' member of the
@@ -653,7 +652,7 @@ static int prism2_config(struct pcmcia_device *link)
                link->irq.Handler = prism2_interrupt;
                ret = pcmcia_request_irq(link, &link->irq);
                if (ret)
-                       goto failed_unlock;
+                       goto failed;
        }
 
        /*
@@ -663,11 +662,11 @@ static int prism2_config(struct pcmcia_device *link)
         */
        ret = pcmcia_request_configuration(link, &link->conf);
        if (ret)
-               goto failed_unlock;
+               goto failed;
 
+       spin_lock_irqsave(&local->irq_init_lock, flags);
        dev->irq = link->irq.AssignedIRQ;
        dev->base_addr = link->io.BasePort1;
-
        spin_unlock_irqrestore(&local->irq_init_lock, flags);
 
        /* Finally, report what we've done */
@@ -698,8 +697,6 @@ 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);