From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH] IB/ipath: use arch_phys_wc_add() and require PAT disabled Date: Mon, 27 Apr 2015 14:38:52 -0400 Message-ID: <1430159932.44548.20.camel@redhat.com> References: <1429730795-6721-1-git-send-email-mcgrof@do-not-panic.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-EsqiffAx5gd7MINrgaaO" Return-path: In-Reply-To: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Luis R. Rodriguez" Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Marciniszyn List-Id: linux-rdma@vger.kernel.org --=-EsqiffAx5gd7MINrgaaO Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2015-04-27 at 09:46 -0700, Luis R. Rodriguez wrote: > On Wed, Apr 22, 2015 at 12:26 PM, Luis R. Rodriguez > wrote: > > From: "Luis R. Rodriguez" > > > > 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. >=20 > 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 ? [ trimmed Cc: list to probably the only people that care ] I would think so. I think we might as well mark this driver as deprecated and put a tentative date on removal while we are at it. Mike, any specific input here? I would suggest mark it deprecated with a planned removal sometime in late 2015/early 2016. --=20 Doug Ledford GPG KeyID: 0E572FDD --=-EsqiffAx5gd7MINrgaaO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJVPoI8AAoJELgmozMOVy/deCUQAJ+LDHINt6Hj3TiM3NAT8q9m IzO5sIIkwzr2zovuuqYeSPMqkflGAY8Sz9+pU/+k+TLCZ5CSfhRdBhAav6ubneOv 6ng/omRtWcUp2FpAINQezECuSKBy4C5McL3k4EQgzRK0NqAKQcWAhfWy3WUpFOdW g2T6ECwo6JlViB9HbqdJ3BRftPp3hZnxL00qtqvKMLuRA0KzemnhqrEktg+Gfdnx trxbuZsk0Okcsz5CJGShZcGS6Fpdh8toyJLlKxr4bsdBnZsOGSoOAHNTyu7P3tLa 5T1g4++2gwJjh6s+HkgJqIJMhj7oiQ8/3t27V638cpaH3o4yHX0xpGtesiK6BVWh Nc4RCfTmoUHZvzJWmE9DCRPkDujPnoZzUnn7S/Unz7m9eDE1oOGxF6H2hGcWJSbG bAfaNs4ClVrc+2QDP8CnN2M4nRRskKN0y1JOvZZ1DvWx8IJ93kJtFJy1nGC+zJUj w92bBuyqTTxKI2A4gL0reCFaVnMotWbo//LgNTcmjwnYIlObIGDXPofgrmGPj7w1 ggX88iQ+k3ULFqlxwRJEZA2kSIxpm7m5Ty9ODUUIzZt94X/PswN1Tv7vGJhzdgVL TzYpj21ByPPHTMX1+0yBA+Z4Un65kB16iUGfdz4r8tDoQ1tEJBAzf7VCFoWpfqqF LuXamWtN8OhYJONrSQe7 =gE1T -----END PGP SIGNATURE----- --=-EsqiffAx5gd7MINrgaaO-- -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html