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References: <20230323090314.22431-1-cai.huoqing@linux.dev> <20230323090314.22431-4-cai.huoqing@linux.dev>
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From:   Dimitris Michailidis <d.michailidis@fungible.com>
Date:   Thu, 23 Mar 2023 10:24:55 -0700
Message-ID: <CAOkoqZk0GRRZb5PyZdQ8THK+oZ+b9PKYUR8jRf2f2e8imEPaGQ@mail.gmail.com>
Subject: Re: [PATCH 4/8] net/fungible: Remove redundant pci_clear_master
To:     Cai Huoqing <cai.huoqing@linux.dev>
Cc:     Derek Chickles <dchickles@marvell.com>,
        Satanand Burla <sburla@marvell.com>,
        Felix Manlunas <fmanlunas@marvell.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Raju Rangoju <rajur@chelsio.com>,
        Dariusz Marcinkiewicz <reksio@newterm.pl>,
        Dimitris Michailidis <dmichail@fungible.com>,
        Yisen Zhuang <yisen.zhuang@huawei.com>,
        Salil Mehta <salil.mehta@huawei.com>,
        Saeed Mahameed <saeedm@nvidia.com>,
        Leon Romanovsky <leon@kernel.org>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Shannon Nelson <shannon.nelson@amd.com>,
        Brett Creeley <brett.creeley@amd.com>, drivers@pensando.io,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Guangbin Huang <huangguangbin2@huawei.com>,
        Jian Shen <shenjian15@huawei.com>, Hao Lan <lanhao@huawei.com>,
        Jie Wang <wangjie125@huawei.com>,
        Long Li <longli@microsoft.com>, Jiri Pirko <jiri@resnulli.us>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, linux-hyperv@vger.kernel.org
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On Thu, Mar 23, 2023 at 2:04=E2=80=AFAM Cai Huoqing <cai.huoqing@linux.dev>=
 wrote:
>
> Remove pci_clear_master to simplify the code,
> the bus-mastering is also cleared in do_pci_disable_device,
> like this:
> ./drivers/pci/pci.c:2197
> static void do_pci_disable_device(struct pci_dev *dev)
> {
>         u16 pci_command;
>
>         pci_read_config_word(dev, PCI_COMMAND, &pci_command);
>         if (pci_command & PCI_COMMAND_MASTER) {
>                 pci_command &=3D ~PCI_COMMAND_MASTER;
>                 pci_write_config_word(dev, PCI_COMMAND, pci_command);
>         }
>
>         pcibios_disable_device(dev);
> }.
> And dev->is_busmaster is set to 0 in pci_disable_device.
>
> Signed-off-by: Cai Huoqing <cai.huoqing@linux.dev>

Acked-by: Dimitris Michailidis <dmichail@fungible.com>


> ---
>  drivers/net/ethernet/fungible/funcore/fun_dev.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/fungible/funcore/fun_dev.c b/drivers/ne=
t/ethernet/fungible/funcore/fun_dev.c
> index 3680f83feba2..a7fbd4cd560a 100644
> --- a/drivers/net/ethernet/fungible/funcore/fun_dev.c
> +++ b/drivers/net/ethernet/fungible/funcore/fun_dev.c
> @@ -746,7 +746,6 @@ void fun_dev_disable(struct fun_dev *fdev)
>         bitmap_free(fdev->irq_map);
>         pci_free_irq_vectors(pdev);
>
> -       pci_clear_master(pdev);
>         pci_disable_device(pdev);
>
>         fun_unmap_bars(fdev);
> @@ -821,7 +820,6 @@ int fun_dev_enable(struct fun_dev *fdev, struct pci_d=
ev *pdev,
>  disable_admin:
>         fun_disable_admin_queue(fdev);
>  free_irq_mgr:
> -       pci_clear_master(pdev);
>         bitmap_free(fdev->irq_map);
>  free_irqs:
>         pci_free_irq_vectors(pdev);
> --
> 2.34.1
>