drm/i915/gsc: mei interrupt top half should be in irq disabled context

[ Upstream commit 8cadce97bf264ed478669c6f32d5603b34608335 ]

MEI GSC interrupt comes from i915. It has top half and bottom half.
Top half is called from i915 interrupt handler. It should be in
irq disabled context.

With RT kernel, by default i915 IRQ handler is in threaded IRQ. MEI GSC
top half might be in threaded IRQ context. generic_handle_irq_safe API
could be called from either IRQ or process context, it disables local
IRQ then calls MEI GSC interrupt top half.

This change fixes A380/A770 GPU boot hang issue with RT kernel.

Fixes: 1e3dc1d8622b ("drm/i915/gsc: add gsc as a mei auxiliary device")
Tested-by: Furong Zhou <furong.zhou@intel.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Junxiao Chang <junxiao.chang@intel.com>
Link: https://lore.kernel.org/r/20250425151108.643649-1-junxiao.chang@intel.com
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
(cherry picked from commit dccf655f69002d496a527ba441b4f008aa5bebbf)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/i915/gt/intel_gsc.c b/drivers/gpu/drm/i915/gt/intel_gsc.c
index bcc3605158dbde43fbac73bd5dd24c9a873549c0..27420ed631d850674856037892ff6b74df04e884 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_gsc.c
+++ b/drivers/gpu/drm/i915/gt/intel_gsc.c
@@ -298,7 +298,7 @@ static void gsc_irq_handler(struct intel_gt *gt, unsigned int intf_id)
        if (gt->gsc.intf[intf_id].irq < 0)
                return;
 
-       ret = generic_handle_irq(gt->gsc.intf[intf_id].irq);
+       ret = generic_handle_irq_safe(gt->gsc.intf[intf_id].irq);
        if (ret)
                drm_err_ratelimited(&gt->i915->drm, "error handling GSC irq: %d\n", ret);
 }