Re: [PATCH v2 10/25] mtd: nand: qcom: reorganize nand devices probing

[Abhishek Sahu <absahu@xxxxxxxxxxxxxx>]

On 2017-08-02 13:51, Archit Taneja wrote:
> On 07/19/2017 05:17 PM, Abhishek Sahu wrote:
> > This is reorganization of exiting code and will not change any
> > functionality. The NAND controller supports multiple NAND device
> > with different page size. The subsequent patch allocate memory
> > which depends upon the maximum number of codewords so this patch
> > reorganizes the NAND device probing. First the ONFI parameter
> > page will be read from each connected device followed by MTD
> > device registration.
>
> Modified the commit message slightly so that it's more clear.
> Looks good otherwise.
>
> "The NAND controller can support multiple NAND devices having different
> page sizes. Future code will require us to allocate memory based on the
> maximum number of codewords among all the devices. We reorganize the 
> NAND
> device probing such that the ONFI parameters are first read for each
> connected device to identify the maximum number of codewords possible,
> and only then proceed with MTD device registration (i.e, call 
> nand_scan_tail
> and mtd_device_register).
>
> This is a reorganization of the existing code and will not change
> any functionality."
>
> Thanks,
> Archit

 Thanks for making it more clear.
 I will amend the commit message in v3.

> > Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
> > ---
> >   drivers/mtd/nand/qcom_nandc.c | 88 
> > +++++++++++++++++++++++++++++--------------
> >   1 file changed, 59 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/qcom_nandc.c 
> > b/drivers/mtd/nand/qcom_nandc.c
> > index 7ecd0f8..8f9e86c 100644
> > --- a/drivers/mtd/nand/qcom_nandc.c
> > +++ b/drivers/mtd/nand/qcom_nandc.c
> > @@ -2059,14 +2059,67 @@ static int qcom_nand_host_init(struct 
> > qcom_nand_controller *nandc,
> >   		return ret;
> >     	ret = qcom_nand_host_setup(host);
> > -	if (ret)
> > -		return ret;
> > +
> > +	return ret;
> > +}
> > +
> > +static int qcom_nand_mtd_register(struct qcom_nand_controller *nandc,
> > +				  struct qcom_nand_host *host,
> > +				  struct device_node *dn)
> > +{
> > +	struct nand_chip *chip = &host->chip;
> > +	struct mtd_info *mtd = nand_to_mtd(chip);
> > +	int ret;
> >     	ret = nand_scan_tail(mtd);
> >   	if (ret)
> >   		return ret;
> >   -	return mtd_device_register(mtd, NULL, 0);
> > +	ret = mtd_device_register(mtd, NULL, 0);
> > +	if (ret)
> > +		nand_cleanup(mtd_to_nand(mtd));
> > +
> > +	return ret;
> > +}
> > +
> > +static int qcom_probe_nand_devices(struct qcom_nand_controller 
> > *nandc)
> > +{
> > +	struct device *dev = nandc->dev;
> > +	struct device_node *dn = dev->of_node, *child;
> > +	struct qcom_nand_host *host, *tmp;
> > +	int ret;
> > +
> > +	for_each_available_child_of_node(dn, child) {
> > +		host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
> > +		if (!host) {
> > +			of_node_put(child);
> > +			return -ENOMEM;
> > +		}
> > +
> > +		ret = qcom_nand_host_init(nandc, host, child);
> > +		if (ret) {
> > +			devm_kfree(dev, host);
> > +			continue;
> > +		}
> > +
> > +		list_add_tail(&host->node, &nandc->host_list);
> > +	}
> > +
> > +	if (list_empty(&nandc->host_list))
> > +		return -ENODEV;
> > +
> > +	list_for_each_entry_safe(host, tmp, &nandc->host_list, node) {
> > +		ret = qcom_nand_mtd_register(nandc, host, child);
> > +		if (ret) {
> > +			list_del(&host->node);
> > +			devm_kfree(dev, host);
> > +		}
> > +	}
> > +
> > +	if (list_empty(&nandc->host_list))
> > +		return -ENODEV;
> > +
> > +	return 0;
> >   }
> >     /* parse custom DT properties here */
> > @@ -2094,10 +2147,8 @@ static int qcom_nandc_parse_dt(struct 
> > platform_device *pdev)
> >   static int qcom_nandc_probe(struct platform_device *pdev)
> >   {
> >   	struct qcom_nand_controller *nandc;
> > -	struct qcom_nand_host *host;
> >   	const void *dev_data;
> >   	struct device *dev = &pdev->dev;
> > -	struct device_node *dn = dev->of_node, *child;
> >   	struct resource *res;
> >   	int ret;
> >   @@ -2151,33 +2202,12 @@ static int qcom_nandc_probe(struct 
> > platform_device *pdev)
> >   	if (ret)
> >   		goto err_setup;
> >   -	for_each_available_child_of_node(dn, child) {
> > -		host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
> > -		if (!host) {
> > -			of_node_put(child);
> > -			ret = -ENOMEM;
> > -			goto err_cs_init;
> > -		}
> > -
> > -		ret = qcom_nand_host_init(nandc, host, child);
> > -		if (ret) {
> > -			devm_kfree(dev, host);
> > -			continue;
> > -		}
> > -
> > -		list_add_tail(&host->node, &nandc->host_list);
> > -	}
> > -
> > -	if (list_empty(&nandc->host_list)) {
> > -		ret = -ENODEV;
> > -		goto err_cs_init;
> > -	}
> > +	ret = qcom_probe_nand_devices(nandc);
> > +	if (ret)
> > +		goto err_setup;
> >     	return 0;
> >   -err_cs_init:
> > -	list_for_each_entry(host, &nandc->host_list, node)
> > -		nand_release(nand_to_mtd(&host->chip));
> >   err_setup:
> >   	clk_disable_unprepare(nandc->aon_clk);
> >   err_aon_clk:

--
Abhishek Sahu
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