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| author |   Anton Blanchard <anton@samba.org> | 2014-05-29 08:15:38 +1000 |
|---|---|---|
| committer |   Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-07-11 13:50:47 +1000 |
| commit | f56029410a13cae3652d1f34788045c40a13ffc7 (patch) | |
| tree | 2f0e1a0d05b6f533eeba3b37b0decc2d6cf84677 /arch/powerpc/kernel/cputable.c | |
| parent | powerpc: Disable RELOCATABLE for COMPILE_TEST with PPC64 (diff) | |
| download | linux-dev-f56029410a13cae3652d1f34788045c40a13ffc7.tar.xz linux-dev-f56029410a13cae3652d1f34788045c40a13ffc7.zip | |
powerpc/perf: Never program book3s PMCs with values >= 0x80000000
We are seeing a lot of PMU warnings on POWER8:
Can't find PMC that caused IRQ
Looking closer, the active PMC is 0 at this point and we took a PMU
exception on the transition from negative to 0. Some versions of POWER8
have an issue where they edge detect and not level detect PMC overflows.
A number of places program the PMC with (0x80000000 - period_left),
where period_left can be negative. We can either fix all of these or
just ensure that period_left is always >= 1.
This patch takes the second option.
Cc: <stable@vger.kernel.org>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/cputable.c')
0 files changed, 0 insertions, 0 deletions