[PATCH] SPI: OMAP: fix over-eager devm_xxx() conversion (was: Re: [CFT 07/11] spi: omap2-mcspi: add DMA engine support)

[Russell King - ARM Linux]

Okay, I'm going to queue this up in my tree for -rc as no one seems to
be listening to any of the emails I've sent on Thursday.

On Thu, Jun 14, 2012 at 03:07:12PM +0100, Russell King - ARM Linux wrote:
> From: Russell King <rmk+kernel at arm.linux.org.uk>
> Subject: [PATCH] SPI: OMAP: fix over-eager devm_xxx() conversion
> 
> 1a77b127ae (OMAP : SPI : use devm_* functions) converted the SPI
> device controller state to use devm_kzalloc().  Unfortunately, this
> is used against an unbound struct device, which results in the
> following when the device is eventually bound to its driver:
> 
> ------------[ cut here ]------------
> WARNING: at /home/rmk/git/linux-rmk/drivers/base/dd.c:257 driver_probe_device+0x78/0x21c()
> Modules linked in:
> Backtrace:
> [<c0017d0c>] (dump_backtrace+0x0/0x10c) from [<c033e208>] (dump_stack+0x18/0x1c) r7:00000000 r6:c01ff28c r5:c040050c r4:00000101
> [<c033e1f0>] (dump_stack+0x0/0x1c) from [<c00337ec>] (warn_slowpath_common+0x58/0x70)
> [<c0033794>] (warn_slowpath_common+0x0/0x70) from [<c0033828>] (warn_slowpath_null+0x24/0x2c)
> [<c0033804>] (warn_slowpath_null+0x0/0x2c) from [<c01ff28c>] (driver_probe_device+0x78/0x21c)
> [<c01ff214>] (driver_probe_device+0x0/0x21c) from [<c01ff49c>] (__driver_attach+0x6c/0x90)
> [<c01ff430>] (__driver_attach+0x0/0x90) from [<c01fda70>] (bus_for_each_dev+0x58/0x98)
> [<c01fda18>] (bus_for_each_dev+0x0/0x98) from [<c01ff0f4>] (driver_attach+0x20/0x28)
> [<c01ff0d4>] (driver_attach+0x0/0x28) from [<c01fe2f4>] (bus_add_driver+0xb4/0x230)
> [<c01fe240>] (bus_add_driver+0x0/0x230) from [<c01ffb24>] (driver_register+0xac/0x138)
> [<c01ffa78>] (driver_register+0x0/0x138) from [<c0215d4c>] (spi_register_driver+0x4c/0x60)
> [<c0215d00>] (spi_register_driver+0x0/0x60) from [<c045414c>] (ks8851_init+0x14/0x1c)
> [<c0454138>] (ks8851_init+0x0/0x1c) from [<c0008770>] (do_one_initcall+0x9c/0x164)
> [<c00086d4>] (do_one_initcall+0x0/0x164) from [<c0436410>] (kernel_init+0x128/0x210)
> [<c04362e8>] (kernel_init+0x0/0x210) from [<c0038754>] (do_exit+0x0/0x72c)
> ---[ end trace 4dcda79f5e89dd84 ]---
> ks8851 spi1.0: message enable is 0
> ks8851 spi1.0: eth0: revision 0, MAC 08:00:28:01:4d:c6, IRQ 194, has EEPROM
> 
> Fix this by partially reverting the original commit.
> 
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---
>  drivers/spi/spi-omap2-mcspi.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
> index 9d3409a..6263b0f 100644
> --- a/drivers/spi/spi-omap2-mcspi.c
> +++ b/drivers/spi/spi-omap2-mcspi.c
> @@ -829,7 +829,7 @@ static int omap2_mcspi_setup(struct spi_device *spi)
>  	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
>  
>  	if (!cs) {
> -		cs = devm_kzalloc(&spi->dev , sizeof *cs, GFP_KERNEL);
> +		cs = kzalloc(sizeof *cs, GFP_KERNEL);
>  		if (!cs)
>  			return -ENOMEM;
>  		cs->base = mcspi->base + spi->chip_select * 0x14;
> @@ -869,6 +869,7 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
>  		cs = spi->controller_state;
>  		list_del(&cs->node);
>  
> +		kfree(cs);
>  	}
>  
>  	if (spi->chip_select < spi->master->num_chipselect) {
> 
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