[Intel-gfx] [PATCH] Align i830 watermark to cache lines

[Thomas Richter]

Hi folks,

as by discussion, the problem with the i830 watermark problems is likely 
that the 830 requires the number of entries in the buffer to be a 
multiple of the cache line size. I provide hereby a small patch
against intel_pm.c that performs the alignment for GEN2 chips.

Tested on the Fujitsu S6010 and R31, seems to work fine here and 
generates reasonable watermarks that do not flicker.

What is a bit unsatisfactory is that, due to the nature of the patch, 
the number of entries in the buffer is always rounded up (necessarily, 
to be conservative), even though for all practical configurations, the 
rounded up size is too large to fit into the buffer, and thus the
rounding direction is "round down" instead of "round up" for all 
realistic settings.

Anyhow, the stuff works.

Greetings,
	Thomas
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