linux-kernel - [PATCH v2 02/14] drm/i915/gsc: skip irq initialization if using polling

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Message-Id: <20220425074901.3991274-3-alexander.usyskin@intel.com>
Date:   Mon, 25 Apr 2022 10:48:49 +0300
From:   Alexander Usyskin <alexander.usyskin@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>
Cc:     Tomas Winkler <tomas.winkler@...el.com>,
        Alexander Usyskin <alexander.usyskin@...el.com>,
        Vitaly Lubart <vitaly.lubart@...el.com>,
        intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        Daniele Ceraolo Spurio <daniele.ceraolospurio@...el.com>
Subject: [PATCH v2 02/14] drm/i915/gsc: skip irq initialization if using polling

From: Vitaly Lubart <vitaly.lubart@...el.com>

Some platforms require the host to poll on the
GSC registers instead of relaying on the interrupts.
For those platforms, irq initialization should be skipped

Signed-off-by: Vitaly Lubart <vitaly.lubart@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@...el.com>
---
 drivers/gpu/drm/i915/gt/intel_gsc.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_gsc.c b/drivers/gpu/drm/i915/gt/intel_gsc.c
index 0e494028b81d..e0236ff1d072 100644
--- a/drivers/gpu/drm/i915/gt/intel_gsc.c
+++ b/drivers/gpu/drm/i915/gt/intel_gsc.c
@@ -40,6 +40,7 @@ struct gsc_def {
 	const char *name;
 	unsigned long bar;
 	size_t bar_size;
+	bool use_polling;
 };
 
 /* gsc resources and definitions (HECI1 and HECI2) */
@@ -117,6 +118,10 @@ static void gsc_init_one(struct drm_i915_private *i915,
 		return;
 	}
 
+	/* skip irq initialization */
+	if (def->use_polling)
+		goto add_device;
+
 	intf->irq = irq_alloc_desc(0);
 	if (intf->irq < 0) {
 		drm_err(&i915->drm, "gsc irq error %d\n", intf->irq);
@@ -129,6 +134,7 @@ static void gsc_init_one(struct drm_i915_private *i915,
 		goto fail;
 	}
 
+add_device:
 	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
 	if (!adev)
 		goto fail;
@@ -182,10 +188,8 @@ static void gsc_irq_handler(struct intel_gt *gt, unsigned int intf_id)
 		return;
 	}
 
-	if (gt->gsc.intf[intf_id].irq < 0) {
-		drm_err_ratelimited(&gt->i915->drm, "GSC irq: irq not set");
+	if (gt->gsc.intf[intf_id].irq < 0)
 		return;
-	}
 
 	ret = generic_handle_irq(gt->gsc.intf[intf_id].irq);
 	if (ret)
-- 
2.32.0