Re: [LINUX PATCH v10 2/2] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Cc: <boris.brezillon@bootlin.com>, <richard@nod.at>,
	<dwmw2@infradead.org>, <computersforpeace@gmail.com>,
	<marek.vasut@gmail.com>, <kyungmin.park@samsung.com>,
	<absahu@codeaurora.org>, <peterpandong@micron.com>,
	<frieder.schrempf@exceet.de>, <linux-mtd@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <michals@xilinx.com>,
	<nagasureshkumarrelli@gmail.com>
Subject: Re: [LINUX PATCH v10 2/2] mtd: rawnand: arasan: Add support for Arasan NAND Flash Controller
Date: Fri, 17 Aug 2018 16:37:33 +0200	[thread overview]
Message-ID: <20180817163733.34d3199c@xps13> (raw)
In-Reply-To: <1534511964-20342-3-git-send-email-naga.sureshkumar.relli@xilinx.com>

Hi Naga,

A user of Xilinx BSP reported a problem with lockdep that I can see is
not yet fixed in this code:

Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> wrote on
Fri, 17 Aug 2018 18:49:24 +0530:

> +static int anfc_probe(struct platform_device *pdev)
> +{
> +	struct anfc_nand_controller *nfc;
> +	struct anfc_nand_chip *anand_chip;
> +	struct device_node *np = pdev->dev.of_node, *child;
> +	struct resource *res;
> +	int err;
> +
> +	nfc = devm_kzalloc(&pdev->dev, sizeof(*nfc), GFP_KERNEL);
> +	if (!nfc)
> +		return -ENOMEM;
> +
> +	init_waitqueue_head(&nfc->controller.wq);

The controller structure has a lock which is not initialized here. You
should not initialize the waitqueue manually neither and instead use
nand_controller_init(&nfc->controller).

> +	INIT_LIST_HEAD(&nfc->chips);
> +	init_completion(&nfc->event);
> +	nfc->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, nfc);
> +	nfc->csnum = -1;
> +	nfc->controller.ops = &anfc_nand_controller_ops;

More to come.

Thanks,
Miquèl