Messages in this thread | | | From | "Luis R. Rodriguez" <> | Date | Mon, 27 Apr 2015 09:46:21 -0700 | Subject | Re: [PATCH] IB/ipath: use arch_phys_wc_add() and require PAT disabled |
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On Wed, Apr 22, 2015 at 12:26 PM, Luis R. Rodriguez <mcgrof@do-not-panic.com> wrote: > From: "Luis R. Rodriguez" <mcgrof@suse.com> > > We are burrying direct access to MTRR code support on > x86 in order to take advantage of PAT. In the future we > also want to make the default behaviour of ioremap_nocache() > to use strong UC, use of mtrr_add() on those systems > would make write-combining void. > > In order to help both enable us to later make strong > UC default and in order to phase out direct MTRR access > code port the driver over to arch_phys_wc_add() and > annotate that the device driver requires systems to > boot with PAT disabled, with the nopat kernel parameter. > > This is a worthy compromise given that the ipath device > driver powers the old HTX bus cards that only work in > AMD systems, while the newer IB/qib device driver > powers all PCI-e cards. The ipath device driver is > obsolete, hardware hard to find and because of this > this its a reasonable compromise to make to require > users of ipath to boot with nopat.
Hey folks, I realize its being discussed whether or not to remove the driver entirely from the kernel but in the meantime, is this a reasonable compromise ?
Luis
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