[AMD Official Use Only - General]
> Without knowing anything about the difficulty of 3), that seems the
> > most attractive to me because we never have to worry about catching
> > every D state transition.
>
> Sure Bjron we came up with below solution without worrying much on very D
> state
> transition and works perfectly fine.
>
> PCI: Add quirk to clear AMD strap_15B8 NO_SOFT_RESET dev 2 f0
>
> The AMD [1022:15b8] USB controller loses some internal functional
> MSI-X context when transitioning from D0 to D3hot. BIOS normally
> traps D0->D3hot and D3hot->D0 transitions so it can save and restore
> that internal context, but some firmware in the field lacks due to
> AMD_15B8_RCC_DEV2_EPF0_STRAP2 NO_SOFT_RESET bit is set.
>
> Hence add quirk to clear AMD_15B8_RCC_DEV2_EPF0_STRAP2 NO_SOFT_RESET
> bit before USB controller initialization during boot.
>
> ---
> drivers/pci/quirks.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 44cab813bf95..0c088fa58ad7 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -12,6 +12,7 @@
> * file, where their drivers can use them.
> */
>
> +#include <asm/amd_nb.h>
> #include <linux/bitfield.h>
> #include <linux/types.h>
> #include <linux/kernel.h>
> @@ -6023,3 +6024,21 @@
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2d, dpc_log_size);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a2f, dpc_log_size);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x9a31, dpc_log_size);
> #endif
> +
> +#define AMD_15B8_RCC_DEV2_EPF0_STRAP2 0x10136008
> +#define
> AMD_15B8_RCC_DEV2_EPF0_STRAP2_NO_SOFT_RESET_DEV2_F0_MASK
> 0x00000080L
> +
> +static void quirk_clear_strap_no_soft_reset_dev2_f0(struct pci_dev *dev)
> +{
> + u32 data;
> +
> + if (!amd_smn_read(0 , AMD_15B8_RCC_DEV2_EPF0_STRAP2, &data)) {
> + data &=
> ~AMD_15B8_RCC_DEV2_EPF0_STRAP2_NO_SOFT_RESET_DEV2_F0_MASK;
> + if (amd_smn_write(0, AMD_15B8_RCC_DEV2_EPF0_STRAP2,
> data))
> + pci_err(dev, "Failed to write data 0x%x\n", data);
> + } else {
> + pci_err(dev, "Failed to read data 0x%x\n", data);
> + }
> +
> +}
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x15b8,
> quirk_clear_strap_no_soft_reset_dev2_f0);
>
>
>
> >
That patch looks good to me. Bjorn may want you to send as a dedicated patch
rather at end of this thread.
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Suggest to also add a Link: tag to the original report.
