Re: [PATCH] nvmet: pci-epf: Move DMA initialization to EPC init callback

[Niklas Cassel <cassel@kernel.org>]

On Tue, Sep 09, 2025 at 01:21:22PM +0200, Niklas Cassel wrote:
> From: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> 
> For DMA initialization to work across all EPC drivers, the DMA
> initialization has to be done in the .init() callback.
> 
> This is because not all EPC drivers will have a refclock (which is often
> needed to access registers of a DMA controller embedded in a PCIe
> controller) at the time the .bind() callback is called.
> 
> However, all EPC drivers are guaranteed to have a refclock by the time
> the .init() callback is called.
> 
> Thus, move the DMA initialization to the .init() callback.
> 
> This change was already done for other EPF drivers in
> commit 60bd3e039aa2 ("PCI: endpoint: pci-epf-{mhi/test}: Move DMA
> initialization to EPC init callback").
> 
> Cc: stable@vger.kernel.org
> Fixes: 0faa0fe6f90e ("nvmet: New NVMe PCI endpoint function target driver")
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Niklas Cassel <cassel@kernel.org>
> ---
>  drivers/nvme/target/pci-epf.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/target/pci-epf.c b/drivers/nvme/target/pci-epf.c
> index 2e78397a7373a..9c5b0f78ce8df 100644
> --- a/drivers/nvme/target/pci-epf.c
> +++ b/drivers/nvme/target/pci-epf.c
> @@ -2325,6 +2325,8 @@ static int nvmet_pci_epf_epc_init(struct pci_epf *epf)
>  		return ret;
>  	}
>  
> +	nvmet_pci_epf_init_dma(nvme_epf);
> +
>  	/* Set device ID, class, etc. */
>  	epf->header->vendorid = ctrl->tctrl->subsys->vendor_id;
>  	epf->header->subsys_vendor_id = ctrl->tctrl->subsys->subsys_vendor_id;
> @@ -2422,8 +2424,6 @@ static int nvmet_pci_epf_bind(struct pci_epf *epf)
>  	if (ret)
>  		return ret;
>  
> -	nvmet_pci_epf_init_dma(nvme_epf);
> -
>  	return 0;
>  }
>  
> -- 
> 2.51.0
> 
> 

Gentle ping


Kind regards,
Niklas