Re: [PATCH V0 08/21] accel/amdxdna: Restore power mode override on AIE4 hardware start

[Lizhi Hou <lizhi.hou@amd.com>]

On 9/25/26 18:34, David Zhang wrote:
> Firmware boots in POWER_MODE_DEFAULT after a reload, so re-send the
> cached user power mode override whenever the hardware starts. This
> ensures the driver cache (ndev->pw_mode) and the firmware power state
> remain consistent when the hardware is reinitialized (e.g. across
> suspend/resume and runtime PM cycles).
>
> Add aie4_restore_power_mode() to re-send the cached override once the
> mailbox is initialized in aie4_pf_hw_start(), aie4_vf_hw_start(), and
> aie4_classic_hw_start(). On a fresh probe, pw_mode is POWER_MODE_DEFAULT
> so this is a no-op. Failure is returned to the caller so hardware start
> aborts cleanly, preventing the driver from continuing with a dead
> management channel if a timeout occurs.
>
> In aie4_classic_hw_start(), if aie4_restore_power_mode() fails after
> aie4_partition_init() has already succeeded, tear down the partition
> before releasing the mailbox so the firmware partition created just
> above isn't leaked on this error path. aie4_vf_hw_start() needs no such
> fix: it never calls aie4_partition_init() itself, so partition teardown
> is not its responsibility; the PF reclaims VF partitions.
>
> Note that system and runtime suspend/resume callbacks (.suspend and
> .resume) for AIE4 are implemented in a subsequent patch ("accel/amdxdna:
> Implement AIE4 suspend and resume"), where the resume handlers invoke
> these hw_start functions and trigger this power mode restoration.
>
> Co-developed-by: Nishad Saraf <nishad.saraf@amd.com>
> Signed-off-by: Nishad Saraf <nishad.saraf@amd.com>
> Signed-off-by: David Zhang <yidong.zhang@amd.com>
> ---
>   drivers/accel/amdxdna/aie4_message.c |  7 ++++--
>   drivers/accel/amdxdna/aie4_pci.c     | 35 ++++++++++++++++++++++++++++
>   drivers/accel/amdxdna/aie4_pci.h     |  3 +++
>   3 files changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/accel/amdxdna/aie4_message.c b/drivers/accel/amdxdna/aie4_message.c
> index a7025995d0e0..f5a17e10cc86 100644
> --- a/drivers/accel/amdxdna/aie4_message.c
> +++ b/drivers/accel/amdxdna/aie4_message.c
> @@ -166,7 +166,10 @@ int aie4_msg_set_power_mode(struct amdxdna_dev_hdl *ndev, u8 power_mode)
>   
>   	ret = aie_send_mgmt_msg_wait(&ndev->aie, &msg);
>   	if (ret)
> -		return ret;
> +		XDNA_WARN(ndev->aie.xdna,
> +			  "Failed to set power mode %u, ret %d", (u32)power_mode, ret);
> +	else
> +		XDNA_DBG(ndev->aie.xdna, "Power mode set to %u", (u32)power_mode);
>   
> -	return 0;
> +	return ret;

Should this be part of patch 07/21?

Lizhi

>   }
> diff --git a/drivers/accel/amdxdna/aie4_pci.c b/drivers/accel/amdxdna/aie4_pci.c
> index 3a063d3ffa94..f72d0dac8263 100644
> --- a/drivers/accel/amdxdna/aie4_pci.c
> +++ b/drivers/accel/amdxdna/aie4_pci.c
> @@ -295,6 +295,27 @@ static int aie4_query(struct amdxdna_dev_hdl *ndev)
>   	return 0;
>   }
>   
> +/*
> + * Firmware always boots in POWER_MODE_DEFAULT after a (re)load, so re-send the
> + * cached user override whenever the hardware starts. This keeps the driver
> + * cache (ndev->pw_mode) and the firmware power state consistent across
> + * suspend/resume and runtime PM cycles. On a fresh probe pw_mode is
> + * POWER_MODE_DEFAULT and this is a no-op.
> + *
> + * Power override is a per-VF property in firmware: each supervisor (VF) stores
> + * its own requested mode and the hypervisor arbitrates globally by taking the
> + * highest mode across all supervisors. A full firmware reload on suspend clears
> + * every supervisor override back to default, so each device type (PF, VF and
> + * classic) must re-send its own cached override on resume.
> + */
> +int aie4_restore_power_mode(struct amdxdna_dev_hdl *ndev)
> +{
> +	if (ndev->pw_mode == POWER_MODE_DEFAULT)
> +		return 0;
> +
> +	return aie4_msg_set_power_mode(ndev, ndev->pw_mode);
> +}
> +
>   static int aie4_pf_hw_start(struct amdxdna_dev_hdl *ndev)
>   {
>   	int ret;
> @@ -311,6 +332,10 @@ static int aie4_pf_hw_start(struct amdxdna_dev_hdl *ndev)
>   	if (ret)
>   		goto mbox_fini;
>   
> +	ret = aie4_restore_power_mode(ndev);
> +	if (ret)
> +		goto mbox_fini;
> +
>   	return 0;
>   
>   mbox_fini:
> @@ -348,6 +373,10 @@ static int aie4_vf_hw_start(struct amdxdna_dev_hdl *ndev)
>   	if (ret)
>   		goto mailbox_fini;
>   
> +	ret = aie4_restore_power_mode(ndev);
> +	if (ret)
> +		goto mailbox_fini;
> +
>   	return 0;
>   
>   mailbox_fini:
> @@ -389,8 +418,14 @@ static int aie4_classic_hw_start(struct amdxdna_dev_hdl *ndev)
>   	if (ret)
>   		goto mailbox_fini;
>   
> +	ret = aie4_restore_power_mode(ndev);
> +	if (ret)
> +		goto partition_fini;
> +
>   	return 0;
>   
> +partition_fini:
> +	aie4_partition_fini(ndev);
>   mailbox_fini:
>   	aie4_mailbox_fini(ndev);
>   stop_fw:
> diff --git a/drivers/accel/amdxdna/aie4_pci.h b/drivers/accel/amdxdna/aie4_pci.h
> index 98b637279257..fd2c50dc8080 100644
> --- a/drivers/accel/amdxdna/aie4_pci.h
> +++ b/drivers/accel/amdxdna/aie4_pci.h
> @@ -87,6 +87,9 @@ int aie4_hwctx_init(struct amdxdna_hwctx *hwctx);
>   void aie4_hwctx_fini(struct amdxdna_hwctx *hwctx);
>   int aie4_cmd_wait(struct amdxdna_hwctx *hwctx, u64 seq, u32 timeout);
>   
> +/* aie4_pci.c */
> +int aie4_restore_power_mode(struct amdxdna_dev_hdl *ndev);
> +
>   /* aie4_sriov.c */
>   #if IS_ENABLED(CONFIG_PCI_IOV)
>   int aie4_sriov_configure(struct amdxdna_dev *xdna, int num_vfs);