From: Jiang Liu <jiang.liu@xxxxxxxxxx> Rebalance DMA channels when CPU hotplug happens to correctly update DMA channel reference count. Signed-off-by: Jiang Liu <liuj97@xxxxxxxxx> --- drivers/dma/dmaengine.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 58bc45c..d3b1c48 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -49,6 +49,7 @@ #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> +#include <linux/cpu.h> #include <linux/device.h> #include <linux/dmaengine.h> #include <linux/hardirq.h> @@ -1003,8 +1004,29 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx) } EXPORT_SYMBOL_GPL(dma_run_dependencies); +static int __cpuinit +hotcpu_rebalance(struct notifier_block *nfb, unsigned long action, void *hcpu) +{ + switch (action) { + case CPU_ONLINE: + case CPU_POST_DEAD: + mutex_lock(&dma_list_mutex); + dma_channel_rebalance(); + mutex_unlock(&dma_list_mutex); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block __refdata dma_cpu_notifier = { + .notifier_call = hotcpu_rebalance, +}; + + static int __init dma_bus_init(void) { + register_hotcpu_notifier(&dma_cpu_notifier); return class_register(&dma_devclass); } arch_initcall(dma_bus_init); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html