Thanks everyone. I will use the dma_get_required_mask() for deciding fusion's descriptor format -----Original Message----- From: Andi Kleen [mailto:andi@xxxxxxxxxxxxxx] Sent: Thursday, April 17, 2008 9:41 PM To: James Bottomley Cc: Prakash, Sathya; linux-scsi@xxxxxxxxxxxxxxx Subject: Re: Query regarding modifying the DMA Mask based on the available memory in the system James Bottomley wrote: > On Thu, 2008-04-17 at 17:06 +0200, Andi Kleen wrote: >> James Bottomley wrote: >>> On Thu, 2008-04-17 at 16:44 +0200, Andi Kleen wrote: >>>>> For drivers that can alter their descriptor types, we have this >>>>> function: >>>>> >>>>> dma_get_required_mask() >>>> Are you sure we have it? It seems to be in drivers/base/platform.c >>>> conditional on ARCH_HAS_DMA_GET_REQUIRED_MASK, but according to my >>>> grep no architecture ever sets that flag. >>> Yes ... positive. That's the default and correct implementation >>> based on the largest addressable physical memory. >> Ok but still the whole thing is completely useless right now. > > Why? At least for aic it performs as advertised: allows the driver to > select the most efficient descriptor format. You were right sorry, I misread the code. Your interpretation is correct. The interface would be correct to use for fusion, although it should be probably extended to IOMMUs too. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
