From: Chris Metcalf Date: Mon, 28 Feb 2011 18:21:52 +0000 (-0500) Subject: arch/tile: fix __ndelay etc to work better X-Git-Tag: v2.6.39-rc1~431^2~19 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=13371731487896a6ef158b1cd74297f40a3da4bb;p=pandora-kernel.git arch/tile: fix __ndelay etc to work better The current implementations of __ndelay and __udelay call a hypervisor service to delay, but the hypervisor service isn't actually implemented very well, and the consensus is that Linux should handle figuring this out natively and not use a hypervisor service. By converting nanoseconds to cycles, and then spinning until the cycle counter reaches the desired cycle, we get several benefits: first, we are sensitive to the actual clock speed; second, we use less power by issuing a slow SPR read once every six cycles while we delay; and third, we properly handle the case of an interrupt by exiting at the target time rather than after some number of cycles. Signed-off-by: Chris Metcalf --- Reading git-diff-tree failed