From 1de178421f1a95de408610c89655ec1d4edb9d29 Mon Sep 17 00:00:00 2001 From: Andrzej Hajda Date: Wed, 8 Mar 2023 14:36:24 +0100 Subject: [PATCH] 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: Rodrigo Vivi Acked-by: Nirmoy Das Reviewed-by: Andi Shyti Signed-off-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20230308133624.2131582-1-andrzej.hajda@intel.com --- drivers/gpu/drm/i915/gt/intel_region_lmem.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.c index f3ad93d..a9a6230 100644 --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c @@ -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; @@ -102,15 +103,25 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915, resource_size_t return; } - /* First disable PCI memory decoding references */ - pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd); - pci_write_config_dword(pdev, PCI_COMMAND, - pci_cmd & ~PCI_COMMAND_MEMORY); + /* + * 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); - _resize_bar(i915, GEN12_LMEM_BAR, rebar_size); + /* First disable PCI memory decoding references */ + pci_read_config_dword(pdev, PCI_COMMAND, &pci_cmd); + pci_write_config_dword(pdev, PCI_COMMAND, + pci_cmd & ~PCI_COMMAND_MEMORY); - pci_assign_unassigned_bus_resources(pdev->bus); - pci_write_config_dword(pdev, PCI_COMMAND, pci_cmd); + _resize_bar(i915, GEN12_LMEM_BAR, rebar_size); + + 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) {} -- 2.7.4