drm/i915/guc: doorbell reset should avoid used doorbells

guc_init_doorbell_hw() borrows the (currently single) GuC client to use
in reinitialising ALL the doorbell registers (as the hardware doesn't
reset them when the GuC is reset). As a prerequisite for accommodating
multiple clients, it should only reset doorbells that are supposed to be
disabled, avoiding those that are marked as in use by any client.

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
This commit is contained in:
Dave Gordon 2016-08-09 15:19:19 +01:00 committed by Tvrtko Ursulin
parent dbd6ef29a7
commit 8888cd0154

View file

@ -697,7 +697,7 @@ guc_client_free(struct drm_i915_private *dev_priv,
}
/*
* Borrow the first client to set up & tear down every doorbell
* Borrow the first client to set up & tear down each unused doorbell
* in turn, to ensure that all doorbell h/w is (re)initialised.
*/
static void guc_init_doorbell_hw(struct intel_guc *guc)
@ -713,6 +713,9 @@ static void guc_init_doorbell_hw(struct intel_guc *guc)
i915_reg_t drbreg = GEN8_DRBREGL(i);
u32 value = I915_READ(drbreg);
if (test_bit(i, guc->doorbell_bitmap))
continue;
err = guc_update_doorbell_id(guc, client, i);
/* Report update failure or unexpectedly active doorbell */
@ -731,6 +734,9 @@ static void guc_init_doorbell_hw(struct intel_guc *guc)
i915_reg_t drbreg = GEN8_DRBREGL(i);
u32 value = I915_READ(drbreg);
if (test_bit(i, guc->doorbell_bitmap))
continue;
if (i != db_id && (value & GUC_DOORBELL_ENABLED))
DRM_DEBUG_DRIVER("Doorbell %d (reg 0x%x) finally 0x%x\n",
i, drbreg.reg, value);