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author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-02-04 23:16:44 +0200 |
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committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-02-05 20:44:43 +0200 |
commit | 39806c3f11e206d03e76521c808a96aedfcc58d9 (patch) | |
tree | 1faa0fefb947c5f2eeae8601e802338d3fe73fed /drivers/gpu/drm/i915/intel_dp.c | |
parent | ab1ab0eb0cb64d1c225bdf42bee067f81c87e2a4 (diff) | |
download | linux-stable-39806c3f11e206d03e76521c808a96aedfcc58d9.tar.gz linux-stable-39806c3f11e206d03e76521c808a96aedfcc58d9.tar.bz2 linux-stable-39806c3f11e206d03e76521c808a96aedfcc58d9.zip |
drm/i915: Include register polling in reg_rw traces
We generally omit register polling from the i915_reg_rw tracepoint.
Understandable since polling could generate a lot of noise in the
trace. The downside is that the trace is incomplete. As a compromise
let's trace the final register value observed while polling. That
should be generally sufficient to observe what the code should be
doing next.
I suppose in some cases it might make sense to also trace the initial
register value, and maybe the number of times we polled. But that
would require a separate tracepoint so let's leave it for the future.
The other users of _NOTRACE() are i915_pmu and i2c bitbanging,
which I decided to leave alone.
Next we should do something to claw back the tracepoints for
planes and whatnot which were switched to _FW() a while back.
I guess just new macros for raw_rw+trace. The question is
what to call it?
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190204211644.21967-1-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp.c')
-rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index d9bc8ee52300..a15d9fd80641 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1061,6 +1061,10 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp) #define C (((status = I915_READ_NOTRACE(ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0) done = wait_event_timeout(dev_priv->gmbus_wait_queue, C, msecs_to_jiffies_timeout(10)); + + /* just trace the final value */ + trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true); + if (!done) DRM_ERROR("dp aux hw did not signal timeout!\n"); #undef C @@ -1227,6 +1231,8 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp, break; msleep(1); } + /* just trace the final value */ + trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true); if (try == 3) { static u32 last_status = -1; |