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Date:   Fri, 2 Jun 2023 08:16:45 +0900
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Subject: Re: [PATCH v5 3/9] PCI: endpoint: Pass EPF device ID to the probe
 function
Content-Language: en-US
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>,
        lpieralisi@kernel.org, kw@linux.com
Cc:     kishon@kernel.org, bhelgaas@google.com, linux-pci@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org
References: <20230601145718.12204-1-manivannan.sadhasivam@linaro.org>
 <20230601145718.12204-4-manivannan.sadhasivam@linaro.org>
From:   Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
In-Reply-To: <20230601145718.12204-4-manivannan.sadhasivam@linaro.org>
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On 6/1/23 23:57, Manivannan Sadhasivam wrote:
> Currently, the EPF probe function doesn't get the device ID argument needed
> to correctly identify the device table ID of the EPF device.
> 
> When multiple entries are added to the "struct pci_epf_device_id" table,
> the probe function needs to identify the correct one. This is achieved by
> modifying the pci_epf_match_id() function to return the match ID pointer
> and passing it to the driver's probe function.
> 
> pci_epf_device_match() function can return bool based on the return value
> of pci_epf_match_id().
> 
> Reviewed-by: Kishon Vijay Abraham I <kishon@kernel.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

[...]

>  static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
> @@ -510,8 +510,12 @@ static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
>  	struct pci_epf *epf = to_pci_epf(dev);
>  	struct pci_epf_driver *driver = to_pci_epf_driver(drv);
>  
> -	if (driver->id_table)
> -		return pci_epf_match_id(driver->id_table, epf);
> +	if (driver->id_table) {
> +		if (pci_epf_match_id(driver->id_table, epf))
> +			return true;
> +		else
> +			return false;

		return pci_epf_match_id(driver->id_table, epf) != NULL;

is simpler. If you do not like this, at least drop the "else" as it is not
necessary at all.

> +	}
>  
>  	return !strcmp(epf->name, drv->name);
>  }
> @@ -520,13 +524,15 @@ static int pci_epf_device_probe(struct device *dev)
>  {
>  	struct pci_epf *epf = to_pci_epf(dev);
>  	struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
> +	const struct pci_epf_device_id *id;
>  
>  	if (!driver->probe)
>  		return -ENODEV;
>  
>  	epf->driver = driver;
> +	id = pci_epf_match_id(driver->id_table, epf);

Not sure that the id variable is that useful.

>  
> -	return driver->probe(epf);
> +	return driver->probe(epf, id);
>  }

-- 
Damien Le Moal
Western Digital Research