Hi James, > > Perhaps if you gave an example of the actual problem you're trying to > fix we could assess if it affects parisc. Let me clarify myself here. Maybe, there is a better solution. /* assign ownership */ desc->status = DEVICE_OWN; /* notify device of new descriptors */ writel(DESC_NOTIFY, doorbell); The difference between writel() and writel_relax() is writel() guarantees memory transactions to be flushed to the device before the register write. writel_relaxed() does not provide any guarantees about the memory and IO operations. Similarly, readl() provides following code to observe the DMA result while readl_relaxed() does not provide this guarantee. Ideally, you want to embed rmb() and wmb() into the writel() and readl() to provide this guarantee. PA-RISC doesn't seem to support neither one of the barrier types. If you are familiar with the architecture, maybe you could guide us here. Is __raw_writeX() enough to provide this guarantee for this architecture? Sinan -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
