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? ;)
> 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
> ---
> 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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