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Date: Mon, 9 Dec 2013 12:31:05 -0800
From: Brian Norris <computersforpeace@gmail.com>
To: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Subject: Re: [PATCH v2] mtd: nand: gpio: Remove unneeded CONFIG_OF
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Cc: linux-mtd@lists.infradead.org, Alexander Shiyan <shc_work@mail.ru>
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On Sat, Dec 07, 2013 at 12:36:49PM -0300, Ezequiel Garcia wrote:
> Since the of_mtd header provides dummy stubs for !CONFIG_OF, it's safe
> to remove the #ifdef CONFIG_OF. Also remove the of_match_ptr guard as
> it's no longer required. Build tested only.
> 
> Cc: Alexander Shiyan <shc_work@mail.ru>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>

Just because we can compile with and without CONFIG_OF doesn't mean the
behavior is equivalent now.

Take a look at gpio_nand_get_io_sync_of(): we allocate and throw away
memory (it's only cleaned up at device removal time):

static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev)
{
	struct resource *r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL);
	u64 addr;

	if (!r || of_property_read_u64(pdev->dev.of_node,
				       "gpio-control-nand,io-sync-reg", &addr))
		return NULL;
...

But I guess this should be fixed anyway, to do this:

static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev)
{
	struct resource *r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL);
	u64 addr;

	if (of_property_read_u64(pdev->dev.of_node,
				 "gpio-control-nand,io-sync-reg", &addr))
		return NULL;

	r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL);
	if (!r)
		return NULL; /* Probably should be PTR_ERR(-ENOMEM), with callee-error-checking */
...

I think we might as well fix this before forcing this quirk onto !OF
builds.

Brian