Messages in this thread | | | Date | Wed, 27 Jan 1999 15:18:43 -0800 (PST) | From | Linux Lists <> | Subject | Re: Big Fix for 2.2.1 |
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On Wed, 27 Jan 1999, Andy Poling wrote: > > On Wed, 27 Jan 1999, Linux Lists wrote: > > Please don't do that. The Cyclades driver supports both ISA and PCI cards, > > and it follows correctly the current definition, by ioremap'ing addresses > > above 1MB and using readX/writeX for _all_ accesses to MMIO resources (in > > ISA or PCI). Doing this change would mean having to test which card I'm > > accessing _every time_ I do a readX/writeX, which is completelly > > unacceptable (for obvious performance reasons). > > Perhaps I'm naive, or missing something really obvious here, but... > > Shouldn't you already know which bus-type of card you're accessing long > before you get to the performance-critical code in any driver?
The issue here is that I thought Linus mentioned a change in the ioremap function, which would require ISA cards to be accessed by read_ISA_X/write_ISA_X and others by readX/writeX. Since my driver uses readX/writeX to access _both_ (PCI and ISA), that would mean having to add the following for every call to this functions:
if (ISA) read_ISA_X/write_ISA_X; else readX/writeX;
Interestingly enough, Linus _didn't_ mention anything about changing the ioremap function (and I have no idea where I got this idea from). Thus, my e-mail is completely unfounded and can be ignored.
Sorry for the unnecessary noise.
Regards and Apologies, Ivan
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