On Fri, Mar 31, 2023 at 01:40:27PM +0200, Stanislaw Gruszka wrote:
> From: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx>
>
> 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_dhot_delay() in drivers/pci/quirks.c . But since
quirk_remove_d3hot_delay()
> 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()
Again.
> for that.
>
> Signed-off-by: Karol Wachowski <karol.wachowski@xxxxxxxxxxxxxxx>
> Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>
> ---
> 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;
d3hot_delay is used after a D0->D3hot transition, after a D3hot->D0
transition, and after the D0->D3hot and D3hot->D0 transitions in
pci_pm_reset().
I assume this device can tolerate removing *all* of those delays,
right?
> ret = pcim_enable_device(pdev);
> if (ret) {
> ivpu_err(vdev, "Failed to enable PCI device: %d\n", ret);
> --
> 2.25.1
>
