From ccc7aad04c95c33407444b1387e42162925e5216 Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Thu, 6 Mar 2014 12:24:08 +0530 Subject: [PATCH 1/2] dmaengine: at_hdmac: use tasklet_kill in teardown As discussed in [1] the tasklet_disable is not a proper function for teardown. We need to ensure irq is disabled, followed by ensuring that don't schedule any more tasklets and then its safe to use tasklet_kill(). Here in at_hdmac driver we use free_irq() before tasklet_kill(). The free_irq() will ensure that the irq is disabled and also wait till all scheduled interrupts are executed by invoking synchronize_irq(). So we need to only do tasklet_kill() after invoking free_irq() [1]: http://lwn.net/Articles/588457/ Reported-by: Thomas Gleixner Acked-by: Nicolas Ferre Reviewed-by: Thomas Gleixner Signed-off-by: Vinod Koul --- drivers/dma/at_hdmac.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index e2c04dc81e2a..c13a3bb0f594 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -1569,7 +1569,6 @@ static int at_dma_remove(struct platform_device *pdev) /* Disable interrupts */ atc_disable_chan_irq(atdma, chan->chan_id); - tasklet_disable(&atchan->tasklet); tasklet_kill(&atchan->tasklet); list_del(&chan->device_node); From 9068b032d0ff9285314d57a88051fe4111bbe73a Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Thu, 6 Mar 2014 12:24:08 +0530 Subject: [PATCH 2/2] dmaengine: pch_dma: use tasklet_kill in teardown As discussed in [1] the tasklet_disable is not a proper function for teardown. We need to ensure irq is disabled, followed by ensuring that don't schedule any more tasklets and then its safe to use tasklet_kill(). Here in pch dma driver we need to use free_irq() before tasklet_kill(). So move up the free_irq() which will ensure that the irq is disabled and also wait till all scheduled interrupts are executed by invoking synchronize_irq(). [1]: http://lwn.net/Articles/588457/ Reported-by: Thomas Gleixner Signed-off-by: Vinod Koul --- drivers/dma/pch_dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c index 61fdc54a3c88..05fa548bd659 100644 --- a/drivers/dma/pch_dma.c +++ b/drivers/dma/pch_dma.c @@ -964,16 +964,16 @@ static void pch_dma_remove(struct pci_dev *pdev) if (pd) { dma_async_device_unregister(&pd->dma); + free_irq(pdev->irq, pd); + list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) { pd_chan = to_pd_chan(chan); - tasklet_disable(&pd_chan->tasklet); tasklet_kill(&pd_chan->tasklet); } pci_pool_destroy(pd->pool); - free_irq(pdev->irq, pd); pci_iounmap(pdev, pd->membase); pci_release_regions(pdev); pci_disable_device(pdev);