On Wed, Jul 31, 2013 at 9:27 PM, Mark Brown <broonie@xxxxxxxxxx> wrote: > On Wed, Jul 31, 2013 at 07:55:27AM -0400, Tejun Heo wrote: > >> If you have DMA / IRQ / command engine deactivations in devm path >> which often is the case with full conversions, freeing any resources >> including DMA areas and host private data in the wrong order is a >> horrible idea. It's worse as it won't really be noticeable in most >> cases. > > It's really only interrupts that affect most devices - if there's DMA or > anything going on after the remove() then as you said earlier the driver > is probably doing something wrong. I think the main point is we should allocate managed resource which is used at interrupt handler before devm_request_irq, and all resources used at interrupt handler should be managed. If we use non-managed resource at interrupt handler, but using managed interrupt handler, things still will go wrong if there is an odd (unexpected) interrupt after we finish deactivation at removal. -- BR, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
