[Intel-gfx] [PATCH 10/11] drm/i915: Improve PSR debugfs status.
Vijay Purushothaman
vijay.a.purushothaman at intel.com
Mon Jun 2 20:24:10 CEST 2014
On 5/16/2014 5:43 AM, Rodrigo Vivi wrote:
> Now we have the active/inactive state for exit and this actually changes the
> HW enable bit the status was a bit confusing for users. So let's provide
> more info.
>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 6636ca2..0ca9376 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1975,10 +1975,12 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
>
> seq_printf(m, "Sink_Support: %s\n", yesno(dev_priv->psr.sink_support));
> seq_printf(m, "Source_OK: %s\n", yesno(dev_priv->psr.source_ok));
> + seq_printf(m, "Enabled: %s\n", yesno(dev_priv->psr.enabled));
> + seq_printf(m, "Active: %s\n", yesno(dev_priv->psr.active));
>
> enabled = HAS_PSR(dev) &&
> I915_READ(EDP_PSR_CTL(dev)) & EDP_PSR_ENABLE;
> - seq_printf(m, "Enabled: %s\n", yesno(enabled));
> + seq_printf(m, "HW Enabled & Active bit: %s\n", yesno(enabled));
>
> if (HAS_PSR(dev))
> psrperf = I915_READ(EDP_PSR_PERF_CNT(dev)) &
Please remove all references to PSR performance counter. This register
is primarily meant as a debug register and its implementation is broken
in the h/w. Whenever the cdclk is gated to save power, the performance
counter is stopped. But when the clk is re-enabled it doesn't reset the
counter. This unnecessarily confuses the end users.. When the system
goes through suspend / resume cycle the performance counter most likely
will transition from a non-zero value to zero.. I already received few
queries from our customers related to this performance customer and they
refuse to believe me when i tell them PSR is still functional when the
performance counter reports 0 :-)
AFAIK this register definition is missing in open source HSW B spec as
well..
Thanks,
Vijay
>
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