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Date:   Thu, 8 Aug 2019 10:25:21 +0100
From:   Andrew Murray <andrew.murray@arm.com>
To:     Denis Efremov <efremov@linux.com>
Cc:     Bjorn Helgaas <bjorn.helgaas@gmail.com>,
        Derek Chickles <dchickles@marvell.com>,
        Satanand Burla <sburla@marvell.com>,
        Felix Manlunas <fmanlunas@marvell.com>, netdev@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] liquidio: Use pcie_flr() instead of reimplementing it
Message-ID: <20190808092520.GR56241@e119886-lin.cambridge.arm.com>
References: <20190808045753.5474-1-efremov@linux.com>
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On Thu, Aug 08, 2019 at 07:57:53AM +0300, Denis Efremov wrote:
> octeon_mbox_process_cmd() directly writes the PCI_EXP_DEVCTL_BCR_FLR
> bit, which bypasses timing requirements imposed by the PCIe spec.
> This patch fixes the function to use the pcie_flr() interface instead.
> 
> Signed-off-by: Denis Efremov <efremov@linux.com>
> ---
>  drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> index 021d99cd1665..614d07be7181 100644
> --- a/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> +++ b/drivers/net/ethernet/cavium/liquidio/octeon_mailbox.c
> @@ -260,9 +260,7 @@ static int octeon_mbox_process_cmd(struct octeon_mbox *mbox,
>  		dev_info(&oct->pci_dev->dev,
>  			 "got a request for FLR from VF that owns DPI ring %u\n",
>  			 mbox->q_no);
> -		pcie_capability_set_word(
> -			oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no],
> -			PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
> +		pcie_flr(oct->sriov_info.dpiring_to_vfpcidev_lut[mbox->q_no]);
>  		break;

It's possible for pcie_flr to fail if the device doesn't become ready soon
enough after reset in which case it returns ENOTTY. I think it's OK not to
test the return value here though, as pci_dev_wait will print a warning
anyway, and I'm not sure what you'd do with it anyway.

Reviewed-by: Andrew Murray <andrew.murray@arm.com>

>  
>  	case OCTEON_PF_CHANGED_VF_MACADDR:
> -- 
> 2.21.0
>