Hi, Am Freitag, 17. September 2010 16:59:25 schrieb Ming Lei: > The warning only means dma_free_coherent is called with irq disabled. > It is not very difficult to fix the warning in usb hcd, but I need to know > why the WARN_ON below is added into dma_free_coherent. > > WARN_ON(irqs_disabled()); > > Anyone know the reason? Hmm... Coherent buffers are ment to be kept for the whole time a driver operates on a device. If such a buffer is freed in an interrupt context (== a momentary action), this is most likely a bug in the driver. At least it is a misuse of the concept of coherent buffers. best regards Wolfgang -- Wahre Worte sind nicht schön - Schöne Worte sind nicht wahr. (Laotse) -- 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
