Date: Fri, 4 Aug 2017 09:49:36 +0200
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Archit Taneja <architt@codeaurora.org>
Cc: Abhishek Sahu <absahu@codeaurora.org>, dwmw2@infradead.org,
        computersforpeace@gmail.com, marek.vasut@gmail.com, richard@nod.at,
        cyrille.pitchen@wedev4u.fr, robh+dt@kernel.org, mark.rutland@arm.com,
        devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
        andy.gross@linaro.org, sricharan@codeaurora.org
Subject: Re: [PATCH v2 10/25] mtd: nand: qcom: reorganize nand devices
 probing
Message-ID: <20170804094936.12e944c4@bbrezillon>
In-Reply-To: <772b9720-cd17-0897-4ee1-836abb748f34@codeaurora.org>
References: <1500464893-11352-1-git-send-email-absahu@codeaurora.org>
        <1500464893-11352-11-git-send-email-absahu@codeaurora.org>
        <772b9720-cd17-0897-4ee1-836abb748f34@codeaurora.org>
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On Wed, 2 Aug 2017 13:51:45 +0530
Archit Taneja <architt@codeaurora.org> 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."

Applied after modifying the commit message as suggested by Archit.

Thanks,

Boris

> 
> Thanks,
> Archit
> 
> > Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> > ---
> >   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:
> >   
>