RE: [EXT] Re: [PATCH net-next v2 1/9] octeon_ep: defer probe if firmware not ready

[Veerasenareddy Burru <vburru@marvell.com>]

> -----Original Message-----
> From: Leon Romanovsky <leon@kernel.org>
> Sent: Wednesday, November 30, 2022 1:25 AM
> To: Veerasenareddy Burru <vburru@marvell.com>
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Liron Himi
> <lironh@marvell.com>; Abhijit Ayarekar <aayarekar@marvell.com>; Sathesh
> B Edara <sedara@marvell.com>; Satananda Burla <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: [EXT] Re: [PATCH net-next v2 1/9] octeon_ep: defer probe if
> firmware not ready
> 
> External Email
> 
> ----------------------------------------------------------------------
> On Tue, Nov 29, 2022 at 05:09:24AM -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>
> > ---
> > 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..aa7d0ced9807 100644
> > --- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> > +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> > @@ -1017,6 +1017,25 @@ static void octep_device_cleanup(struct
> octep_device *oct)
> >  	oct->conf = NULL;
> >  }
> >
> > +static u8 get_fw_ready_status(struct pci_dev *pdev)
> 
> Please change this function to return bool, you are not interested in status.
> 
Yes, we can just return bool; Thanks for the suggestion. Will implement this.
> > +{
> > +	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) {
> 
> Success oriented flow, plase
> if (vsec_id != FW_STATUS_VSEC_ID)
>  cotitnue;
> 
> ....
> 
Sure, will change this.
> > +			pci_read_config_byte(pdev, (pos + 8), &status);
> > +			dev_info(&pdev->dev, "Firmware ready %u\n",
> status);
> > +			return status;
> > +		}
> > +	}
> > +	return 0;
> > +}
> > +
> >  /**
> >   * octep_probe() - Octeon PCI device probe handler.
> >   *
> > @@ -1053,6 +1072,13 @@ static int octep_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
> >  	pci_enable_pcie_error_reporting(pdev);
> >  	pci_set_master(pdev);
> >
> > +#define FW_STATUS_READY    1
> > +	if (get_fw_ready_status(pdev) != FW_STATUS_READY) {
> 
> No need to this new define if you change get_fw_ready_status() to return
> true/false.
We will change this to true/false.
> 
> And I think that you can put this check earlier in octep_probe().
We will check and move this to earlier point in octep_probe().

Thanks
> 
> Thanks
> 
> > +		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
> >