[PATCH] fix-lid302dl-bitbang-all-the-way-baby.patch

[andrzej zaborowski]

2008/8/27 Andy Green <andy at openmoko.com>:
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> Somebody in the thread at some point said:
> | Somebody in the thread at some point said:
> | | Somebody in the thread at some point said:
> | |
> | | | I merged this into the stable 2.6.26 git and it breaks battery
> again :(
> | | |
> | | | It also didn't solve my lockup. It took a little longer, but first
> | | | input3 stopped then input2 just as before.
> | | |
> | | | There is something odd with the gpio stuff as battery was broken first
> | | | by some old cfgpin calls in the led driver. Perhaps all gpio accesses
> | | | should be made atomic if they are not already.
> | |
> | | You are right about that, it is read-modify-write action.  But I can't
> | | see how it trashes HDQ or somehow HDQ pin cfg stuff could trash motion
> | | sensor poll.
> |
> | It is very suspicious that the ersatz chip selects for the motion
> | sensors are on D12 and D13, and HDQ pin is on D14...
>
> When battery gets broken, what does that look like?  What's the first
> indication of trouble?
>
> I noticed problems with it on 2.6.27 (only) and changed the timer we use
> for FIQ, that seemed to solve it.  The HDQ traffic was wrong duration, I
> guessed it was something to do with tickless stuff changing the shared
> prescaler on timer 3 and 4 that we use for FIQ.

In theory it can only change anything once you write 1 into
/sys/devices/system/timer/timer0/dyn_tick , without that no prescaler
or other registers are affected.

Cheers