[PATCH 0/2] [lucid] LP#538377 -- Radeon HDMI output turns off randomly

Chase Douglas chase.douglas at canonical.com
Thu Apr 8 19:11:42 UTC 2010

On Thu, Apr 8, 2010 at 8:13 AM, Andy Whitcroft <apw at canonical.com> wrote:
> This seems to be triggered by PLL setup issues.  There is a somewhat
> larger than I would like rewrite of this whole algorithm in mainline.
> This seems to fix the issue for the reporters.
> I think we want this for Lucid, but it is rather large.  Comments?

I'm concerned by the size of the patches as well. It sets a new
default algo for avivo cards. I think we should put the patches in,
but add a third UBUNTU SAUCE patch that reverts the default to the
legacy pll algo (by initializing radeon_new_pll to 0 instead of -1).
Since the bug symptoms are that the display works for a while and then
all of a sudden turns off, this should at least allow people to still
boot. In the release notes we can note that there's a new pll algo
that can be enabled by adding the following to

options radeon new_pll=1

Or perhaps we ship it with it commented out so people can more easily enable it?

There's also another pll patch that fixes some LCD issues [1], but it
touches both the new and legacy algos, so I'd be afraid to apply it
without good reason.

So, with a reverted default I would say Ack to both patches. But
without, I'd say Nack to both.

[1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=86cb2bbfda2cf402aee46779ee90bbb7d915482b

-- Chase

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