[PATCH] mtd: fsl-quadspi: Fix module unbound

[Huang Shijie]

On Mon, Jan 05, 2015 at 10:49:31PM -0800, Brian Norris wrote:
> Hi,
> 
> On Fri, Dec 05, 2014 at 07:14:46PM -0200, Fabio Estevam wrote:
> > From: Fabio Estevam <fabio.estevam at freescale.com>
> > 
> > When removing the fsl-quadspi module and running 'cat /proc/mtd' afterwards,
> > we see garbage data like:
> > 
> > $ rmmod  fsl-quadspi
> > $ cat /proc/mtd
> > dev:    size   erasesize  name
> > mtd0: 00000000 00000000 "(null)"
> > mtd0: 00000000 00000000 "(null)"
> > mtd0: 00000000 00000000 "(null)"
> > ...
> > mtd0: a22296c6c756e28 00000000 "(null)"
> > mtd0: a22296c6c756e28 3064746d "(null)"
> > 
> > The reason for this is due to the wrong mtd index used in
> > mtd_device_unregister() in the remove function.
> > 
> > We need to keep the mtd index aligned with the one used in the probe function,
> > which means we need to take into account the 'has_second_chip' property.
> > 
> > Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> > ---
> >  drivers/mtd/spi-nor/fsl-quadspi.c | 19 +++++++++++++------
> >  1 file changed, 13 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> > index 39763b9..4b468a9 100644
> > --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> > +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> > @@ -227,6 +227,7 @@ struct fsl_qspi {
> >  	u32 nor_num;
> >  	u32 clk_rate;
> >  	unsigned int chip_base_addr; /* We may support two chips. */
> > +	bool has_second_chip;
> >  };
> >  
> >  static inline int is_vybrid_qspi(struct fsl_qspi *q)
> > @@ -783,7 +784,6 @@ static int fsl_qspi_probe(struct platform_device *pdev)
> >  	struct spi_nor *nor;
> >  	struct mtd_info *mtd;
> >  	int ret, i = 0;
> > -	bool has_second_chip = false;
> >  	const struct of_device_id *of_id =
> >  			of_match_device(fsl_qspi_dt_ids, &pdev->dev);
> >  
> > @@ -860,14 +860,14 @@ static int fsl_qspi_probe(struct platform_device *pdev)
> >  		goto irq_failed;
> >  
> >  	if (of_get_property(np, "fsl,qspi-has-second-chip", NULL))
> 
> Huh? Why was this property even needed in the first place? It seems
> oddly specific, without actually being very explanatory/descriptive.
The qspi controller can connect with two SPI flashes at the same time.
Most of the time, we only connect one flash to it.

Use this property can makes the DTS file simple. If we remove this
propery, we have to add a long same child node for the qspi. 

But i think it is ok to remove it, if Brian thinks it is odd.

Hi Fabio, could you please create a correct patch based on Brian's sample patch?

If you do not have time, please tell me. :)

thanks
Huang Shijie