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Date: Thu, 17 Aug 2023 11:05:57 +0300
From: Leon Romanovsky <leon@kernel.org>
To: Yu Liao <liaoyu15@huawei.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
	kuba@kernel.org, pabeni@redhat.com, shannon.nelson@amd.com,
	liwei391@huawei.com
Subject: Re: [PATCH v2 net-next] pds_core: remove redundant pci_clear_master()
Message-ID: <20230817080557.GG22185@unreal>
References: <20230817025709.2023553-1-liaoyu15@huawei.com>
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In-Reply-To: <20230817025709.2023553-1-liaoyu15@huawei.com>

On Thu, Aug 17, 2023 at 10:57:09AM +0800, Yu Liao wrote:
> do_pci_disable_device() disable PCI bus-mastering as following:
> 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 &= ~PCI_COMMAND_MASTER;
> 				pci_write_config_word(dev, PCI_COMMAND, pci_command);
> 		}
> 
> 		pcibios_disable_device(dev);
> }
> And pci_disable_device() sets dev->is_busmaster to 0.
> 
> pci_enable_device() is called only once before calling to
> pci_disable_device() and such pci_clear_master() is not needed. So remove
> redundant pci_clear_master().
> 
> Also rename goto label 'err_out_clear_master' to 'err_out_disable_device'.
> 
> Signed-off-by: Yu Liao <liaoyu15@huawei.com>
> ---
> v1 -> v2:
> - add explanation why pci_disable_device() disables PCI bus-mastering
> - rename goto label 'err_out_clear_master' to 'err_out_disable_device' 
> ---
>  drivers/net/ethernet/amd/pds_core/main.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>