Hi shawn, On 08/10/2017 05:14 PM, Shawn Lin wrote: > Hi Jeffy > > On 2017/8/10 16:39, jeffy wrote: >> Hi shawn, >> >> On 08/10/2017 04:21 PM, Shawn Lin wrote: >>> With CONFIG_DEBUG_SHIRQ enabled, the irq tear down routine >>> would still access the irq handler registed as a shard irq. >>> Per the comment within the function of __free_irq, it says >>> "It's a shared IRQ -- the driver ought to be prepared for >>> an IRQ event to happen even now it's being freed". However >>> when failing to probe the driver, it may disable the clock >>> for accessing the register and the following check for shared >>> irq state would call the irq handler which accesses the register >>> w/o the clk enabled. That will hang the system forever. >> >> i think this extra irq call is to make sure it's safe to get a shared >> irq when we are freeing it, and we would not get this irq after freed it. >> >> so maybe just call devm_free_irq before disable clks(and other >> required resources for the irq handler)? and also do it in the >> rockchip_pcie_remove. > > That works since we free it and the following devm_irq_release would > bail out early. But I know sure if it is the real intention of the > devm_ irq stuff, although devm_free_irq should be called to free the > IRQ separately if we want. At least that is so explicit that folks will > know that, as more from the top view, it seems only a little drivers > there call devm_free_irq for this case by looking into some more > drivers(Still no any PCIe drivers do that). > > Not sure if their systems are robust enough that could access the > register w/o clk, even without power domain enabled. maybe we can use request_irq & free_irq directly?
