From: Luis R. Rodriguez Date: Mon, 15 Jun 2015 08:28:16 +0000 (+0200) Subject: x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled X-Git-Tag: omap-for-v4.2/fixes-rc1^2~170^2^3~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1bf1735b478008c30acaff18ec6f4a3ff211c28a;p=pandora-kernel.git x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled 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 behavior of ioremap_nocache() to use strong UC, at which point the 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 the arch_phys_wc_add() API and annotate that the device driver requires systems to boot with PAT disabled, with the 'nopat' kernel parameter. This is a workable compromise given that the hardware is really rare these days, and perhaps only some lost souls stuck with obsolete hardware are expected to be using this feature of the device driver. Signed-off-by: Luis R. Rodriguez Signed-off-by: Borislav Petkov Acked-by: Andy Walls Acked-by: Mauro Carvalho Chehab Cc: Andrew Morton Cc: Andy Lutomirski Cc: Antonino Daplas Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Gerst Cc: Daniel Vetter Cc: Dave Airlie Cc: Dave Hansen Cc: Denys Vlasenko Cc: Doug Ledford Cc: H. Peter Anvin Cc: Jean-Christophe Plagniol-Villard Cc: Juergen Gross Cc: Linus Torvalds Cc: Michael S. Tsirkin Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Roger Pau Monné Cc: Stefan Bader Cc: Suresh Siddha Cc: Thomas Gleixner Cc: Ville Syrjälä Cc: bhelgaas@google.com Cc: konrad.wilk@oracle.com Cc: linux-media@vger.kernel.org Cc: tomi.valkeinen@ti.com Cc: toshi.kani@hp.com Link: http://lkml.kernel.org/r/1434053994-2196-2-git-send-email-mcgrof@do-not-panic.com Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed