| From | Paul Gortmaker <> | Subject | [34-longterm 065/247] hostap_cs: fix sleeping function called from invalid context | Date | Thu, 23 Jun 2011 13:32:13 -0400 |
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From: Stanislaw Gruszka <sgruszka@redhat.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
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> --- drivers/net/wireless/hostap/hostap_cs.c | 15 ++++++--------- 1 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/hostap/hostap_cs.c b/drivers/net/wireless/hostap/hostap_cs.c index f33e18e..e436aca 100644 --- 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); -- 1.7.4.4
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