Hi Kevin,
Thanks a lot for your comments.
On 05/28/2013 09:45 PM, Kevin Hilman wrote:
Andrii Tseglytskyi <andrii.tseglytskyi@xxxxxx> writes:
From: Nishanth Menon <nm@xxxxxx>
vpboundsintr_en is available inside the IP block as an re-sycned
version and one which is not. Due to this, there is an 1 sysclk
cycle window where interruptz could be asserted low for 1 cycle.
^^^
Is that the way the cool kidz are spelling interrupts these days? ;)
Oh! Shame on me. Thank you for catching this :)
IF, intr_en is cleared on the exact same cycle as the irqclr, an
additional pulse is generated which indicates for VP that
an additional adjustment of voltage is required.
This results in VP doing two voltage adjustments for the SRERR
(based on configuration, upto 4 steps), instead of the needed
1 step.
Due to the unexpected pulse from AVS which breaks the AVS-VP
communication protocol, VP also ends up in a stuck condition by
entering a state where VP module remains non-responsive
to any futher AVS adjustment events. This creates the symptom
called "TRANXDONE Timeout" scenario.
By disabling errgen prior to disable of intr_en, this situation
can be avoided.
Signed-off-by: Vincent Bour <v-bour@xxxxxx>
Signed-off-by: Leonardo Affortunati <l-affortunati@xxxxxx>
Signed-off-by: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Andrii.Tseglytskyi <andrii.tseglytskyi@xxxxxx>
From Documentation/SubbmittingPatches:
"If a person was not directly involved in the preparation or handling
of a patch but wishes to signify and record their approval of it then
they can arrange to have an Acked-by: line added to the patch's
changelog."
Are all of the tags above co-authors or on the delivery path? I suspect
an Acked-by or Reviewed-by is more appropriate here.
Otherwise, patch itself looks fine.
Kevin
This patch was developed by Nishanth, he is the author of the code.
Patch is the result of 2-week debug session. Vincent, Leonardo and
Nishanth were involved to that debug session.
My contribution to this patch - is sending it to upstream, no more than
this.
Could you please suggest - who should remain in Signed-offs ?
---
drivers/power/avs/smartreflex.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/power/avs/smartreflex.c b/drivers/power/avs/smartreflex.c
index 6b2238b..f34d34d 100644
--- a/drivers/power/avs/smartreflex.c
+++ b/drivers/power/avs/smartreflex.c
@@ -449,12 +449,17 @@ int sr_disable_errgen(struct voltagedomain *voltdm)
return -EINVAL;
}
- /* Disable the interrupts of ERROR module */
- sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
-
/* Disable the Sensor and errorgen */
sr_modify_reg(sr, SRCONFIG, SRCONFIG_SENENABLE | SRCONFIG_ERRGEN_EN, 0);
+ /*
+ * Disable the interrupts of ERROR module
+ * NOTE: modify is a read, modify,write - an implicit OCP barrier
+ * which is required is present here - sequencing is critical
+ * at this point (after errgen is disabled, vpboundint disable)
+ */
+ sr_modify_reg(sr, errconfig_offs, vpboundint_en | vpboundint_st, 0);
+
return 0;
}
--
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