Re: [PATCH net-next v3 1/7] octeon_ep: defer probe if firmware not ready

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
To: Veerasenareddy Burru <vburru@marvell.com>
Cc: <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<aayarekar@marvell.com>, <sedara@marvell.com>,
	<sburla@marvell.com>, <linux-doc@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	"Eric Dumazet" <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Subject: Re: [PATCH net-next v3 1/7] octeon_ep: defer probe if firmware not ready
Date: Tue, 14 Feb 2023 18:32:05 +0100	[thread overview]
Message-ID: <Y+vFlfakHj33DEkt@boxer> (raw)
In-Reply-To: <20230214051422.13705-2-vburru@marvell.com>

On Mon, Feb 13, 2023 at 09:14:16PM -0800, Veerasenareddy Burru wrote:
> Defer probe if firmware is not ready for device usage.
> 
> Signed-off-by: Veerasenareddy Burru <vburru@marvell.com>
> Signed-off-by: Abhijit Ayarekar <aayarekar@marvell.com>
> Signed-off-by: Satananda Burla <sburla@marvell.com>
> ---
> v2 -> v3:
>  * fix review comments
>    https://lore.kernel.org/all/Y4chWyR6qTlptkTE@unreal/
>    - change get_fw_ready_status() to return bool
>    - fix the success oriented flow while looking for
>      PCI extended capability
>  
> v1 -> v2:
>  * was scheduling workqueue task to wait for firmware ready,
>    to probe/initialize the device.
>  * now, removed the workqueue task; the probe returns EPROBE_DEFER,
>    if firmware is not ready.
>  * removed device status oct->status, as it is not required with the
>    modified implementation.
> 
>  .../ethernet/marvell/octeon_ep/octep_main.c   | 26 +++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> index 5a898fb88e37..5620df4c6d55 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> @@ -1017,6 +1017,26 @@ static void octep_device_cleanup(struct octep_device *oct)
>  	oct->conf = NULL;
>  }
>  
> +static bool get_fw_ready_status(struct pci_dev *pdev)
> +{
> +	u32 pos = 0;
> +	u16 vsec_id;
> +	u8 status;
> +
> +	while ((pos = pci_find_next_ext_capability(pdev, pos,
> +						   PCI_EXT_CAP_ID_VNDR))) {
> +		pci_read_config_word(pdev, pos + 4, &vsec_id);
> +#define FW_STATUS_VSEC_ID  0xA3
> +		if (vsec_id != FW_STATUS_VSEC_ID)
> +			continue;
> +
> +		pci_read_config_byte(pdev, (pos + 8), &status);
> +		dev_info(&pdev->dev, "Firmware ready status = %u\n", status);
> +		return status ? true : false;

nit:

return !!status;

?

> +	}
> +	return false;
> +}
> +
>  /**
>   * octep_probe() - Octeon PCI device probe handler.
>   *
> @@ -1053,6 +1073,12 @@ static int octep_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>  	pci_enable_pcie_error_reporting(pdev);
>  	pci_set_master(pdev);
>  
> +	if (!get_fw_ready_status(pdev)) {
> +		dev_notice(&pdev->dev, "Firmware not ready; defer probe.\n");
> +		err = -EPROBE_DEFER;
> +		goto err_alloc_netdev;
> +	}
> +
>  	netdev = alloc_etherdev_mq(sizeof(struct octep_device),
>  				   OCTEP_MAX_QUEUES);
>  	if (!netdev) {
> -- 
> 2.36.0
>