On Wed, Mar 08, 2023 at 02:36:24PM +0100, Andrzej Hajda wrote: > 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)
oh, I really dislike this with_rpm... a get and put directly would end up with a much clear patch... :/ but anyway: Reviewed-by: Rodrigo Vivi <[email protected]> > > Signed-off-by: Andrzej Hajda <[email protected]> > --- > Please ignore resend of v1, my mistake. > > Regards > Andrzej > --- > 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 89fdfc67f8d1e0..2a3217e2890fc7 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) {} > -- > 2.34.1 >
