Re: [PATCH] Clarify pci_iomap() usage for MMIO-only devices

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Linus Torvalds wrote:
The old situation with SATA drivers that had

	if (iomem)
		writel(..)
	else
		outl(..)

in the cases that needed it (and used hardcoded writel/outl in the cases that didn't) was an example of code that "in theory" is faster. But dammit, in practice that mattered not one whit, and what iomap() tries to do is to attack the _real_ problem we had in that area.
Which had nothing what-so-ever to do with any branches.
And none of those issues are a factor at all in ath5k (which spawned 
this sub-discussion), or indeed many other drivers.  The above code you 
cite is -generic-, hardware agnostic code.
Most new hardware is MMIO-only, making ioread32() only for drivers that 
care about legacy IO support, something that is being slowly phased out. 
 e.g. legacy IDE, legacy 10/100 mbps ethernet NICs with the dual 
MMIO/PIO register spaces.
	Jeff



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