Commit 1de17842 authored by Andrzej Hajda's avatar Andrzej Hajda
Browse files

drm/i915/gt: prevent forcewake releases during BAR resize 

Tests on DG2 machines show that releasing forcewakes during BAR resize
results later in forcewake ack timeouts. Since forcewakes can be realeased
asynchronously the simplest way to prevent it is to get all forcewakes
for duration of BAR resizing.

v2: hold rpm as well during resizing (Rodrigo)

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6530
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7853


Reviewed-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: default avatarNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: default avatarAndrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230308133624.2131582-1-andrzej.hajda@intel.com
parent 83842357

drivers/gpu/drm/i915/gt/intel_region_lmem.c

+18 −7
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t 
	struct resource *root_res;

	resource_size_t rebar_size;

	resource_size_t current_size;

	intel_wakeref_t wakeref;

	u32 pci_cmd;

	int i;
@@ -102,6 +103,14 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t 
		return;

	}



	/*

	 * Releasing forcewake during BAR resizing results in later forcewake

	 * ack timeouts and former can happen any time - it is asynchronous.

	 * Grabbing all forcewakes prevents it.

	 */

	with_intel_runtime_pm(i915->uncore.rpm, wakeref) {

		intel_uncore_forcewake_get(&i915->uncore, FORCEWAKE_ALL);



		/* First disable PCI memory decoding references */

		pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd);

		pci_write_config_dword(pdev, PCI_COMMAND,
@@ -111,6 +120,8 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t 


		pci_assign_unassigned_bus_resources(pdev->bus);

		pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd);

		intel_uncore_forcewake_put(&i915->uncore, FORCEWAKE_ALL);

	}

}

#else

static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t lmem_size) {}