[PATCH AUTOSEL 6.3 26/44] accel/ivpu: Remove D3hot delay for Meteorlake

[Sasha Levin]

From: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx>

[ Upstream commit cb949ce504e829193234e26cb3042bb448465d52 ]

VPU on MTL has hardware optimizations and does not require 10ms
D0 - D3hot transition delay imposed by PCI specification (PCIe
r6.0, sec 5.9.) .

The delay removal is traditionally done by adding PCI ID to
quirk_remove_d3hot_delay() in drivers/pci/quirks.c . But since
we do not need that optimization before driver probe and we
can better specify in the ivpu driver on what (future) hardware
use the optimization, we do not use quirk_remove_d3hot_delay()
for that.

Signed-off-by: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>
Reviewed-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230403121545.2995279-1-stanislaw.gruszka@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/accel/ivpu/ivpu_drv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c
index 6a320a73e3ccf..8396db2b52030 100644
--- a/drivers/accel/ivpu/ivpu_drv.c
+++ b/drivers/accel/ivpu/ivpu_drv.c
@@ -437,6 +437,10 @@ static int ivpu_pci_init(struct ivpu_device *vdev)
 	/* Clear any pending errors */
 	pcie_capability_clear_word(pdev, PCI_EXP_DEVSTA, 0x3f);
 
+	/* VPU MTL does not require PCI spec 10m D3hot delay */
+	if (ivpu_is_mtl(vdev))
+		pdev->d3hot_delay = 0;
+
 	ret = pcim_enable_device(pdev);
 	if (ret) {
 		ivpu_err(vdev, "Failed to enable PCI device: %d\n", ret);
-- 
2.39.2