drm/i915/psr: Control PSR interrupts via debugfs

Interrupts other than the one for AUX errors are required only for debug,
so unmask them via debugfs when the user requests debug.

User can make such a request with
echo 1 > <DEBUG_FS>/dri/0/i915_edp_psr_debug

There are no locks to serialize PSR debug enabling from
irq_postinstall() and debugfs for simplicity. As irq_postinstall() is
called only during module initialization/resume and IGT subtests
aren't expected to modify PSR debug at those times, we should be safe.

v2: Unroll loops (Ville)
    Avoid resetting error mask bits.

v3: Unmask interrupts in postinstall() if debug was still enabled.
    Avoid RMW (Ville)

v4: Avoid extra IMR write introduced in the previous version.(Jose)
    Style changes, renames (Jose).

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405013717.24254-1-dhinakaran.pandiyan@intel.com

1 files changed, 35 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e0274f41bc76..a6c70ff4ae5a 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2690,6 +2690,39 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
 	return 0;
 }
 
+static int
+i915_edp_psr_debug_set(void *data, u64 val)
+{
+	struct drm_i915_private *dev_priv = data;
+
+	if (!CAN_PSR(dev_priv))
+		return -ENODEV;
+
+	DRM_DEBUG_KMS("PSR debug %s\n", enableddisabled(val));
+
+	intel_runtime_pm_get(dev_priv);
+	intel_psr_irq_control(dev_priv, !!val);
+	intel_runtime_pm_put(dev_priv);
+
+	return 0;
+}
+
+static int
+i915_edp_psr_debug_get(void *data, u64 *val)
+{
+	struct drm_i915_private *dev_priv = data;
+
+	if (!CAN_PSR(dev_priv))
+		return -ENODEV;
+
+	*val = READ_ONCE(dev_priv->psr.debug);
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(i915_edp_psr_debug_fops,
+			i915_edp_psr_debug_get, i915_edp_psr_debug_set,
+			"%llu\n");
+
 static int i915_sink_crc(struct seq_file *m, void *data)
 {
 	struct drm_i915_private *dev_priv = node_to_i915(m->private);
@@ -4862,7 +4895,8 @@ static const struct i915_debugfs_files {
 	{"i915_guc_log_relay", &i915_guc_log_relay_fops},
 	{"i915_hpd_storm_ctl", &i915_hpd_storm_ctl_fops},
 	{"i915_ipc_status", &i915_ipc_status_fops},
-	{"i915_drrs_ctl", &i915_drrs_ctl_fops}
+	{"i915_drrs_ctl", &i915_drrs_ctl_fops},
+	{"i915_edp_psr_debug", &i915_edp_psr_debug_fops}
 };
 
 int i915_debugfs_register(struct drm_i915_private *dev_priv)