[PATCH] accel/ivpu: Remove D3hot delay for Meteorlake

From: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
To: dri-devel@lists.freedesktop.org
Cc: Oded Gabbay <ogabbay@kernel.org>,
	Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>,
	Jeffrey Hugo <quic_jhugo@quicinc.com>,
	linux-pci@vger.kernel.org,
	Karol Wachowski <karol.wachowski@linux.intel.com>,
	Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Subject: [PATCH] accel/ivpu: Remove D3hot delay for Meteorlake
Date: Fri, 31 Mar 2023 13:40:27 +0200	[thread overview]
Message-ID: <20230331114027.2803100-1-stanislaw.gruszka@linux.intel.com> (raw)

From: Karol Wachowski <karol.wachowski@linux.intel.com>

VPU on MTL has hardware optimizations and does not require 10ms
D0 - D3hot transition delay imposed by PCI specification.

The delay removal is traditionally done by adding PCI ID to
quirk_remove_dhot_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_dhot_delay()
for that.

Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
---
 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 3be4a5a2b07a..cf9925c0a8ad 100644
--- a/drivers/accel/ivpu/ivpu_drv.c
+++ b/drivers/accel/ivpu/ivpu_drv.c
@@ -442,6 +442,10 @@ 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);
-- 
2.25.1

