MTD: make panic_write() conditional to CONFIG_MTD_OOPS

The mtdoops driver is the only user of the panic_write callback
make all panic_write related code conditionnal to CONFIG_MTD_OOPS
so we can save some code. Since CONFIG_MTD_OOPS can be a module
use the newly introduced IS_ENABLED() macro to cope with that.

It is safe to define the panic_write callback as NULL when
CONFIG_MTD_OOPS is disabled since the mtdoops drivers check for the
callback being non-NULL and returns an error if this the case.

Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
---
 drivers/mtd/mtdpart.c              |    5 +++++
 drivers/mtd/nand/nand_base.c       |    7 +++++++
 drivers/mtd/onenand/onenand_base.c |    5 +++++
 3 files changed, 17 insertions(+), 0 deletions(-)

On Tue, Jan 10, 2012 at 05:51:03PM +0100, Florian Fainelli wrote:
> The mtdoops driver is the only user of the panic_write callback
> make all panic_write related code conditionnal to CONFIG_MTD_OOPS
> so we can save some code. Since CONFIG_MTD_OOPS can be a module
> use the newly introduced IS_ENABLED() macro to cope with that.
> 
> It is safe to define the panic_write callback as NULL when
> CONFIG_MTD_OOPS is disabled since the mtdoops drivers check for the
> callback being non-NULL and returns an error if this the case.
> 
> Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
> ---
>  drivers/mtd/mtdpart.c              |    5 +++++
>  drivers/mtd/nand/nand_base.c       |    7 +++++++
>  drivers/mtd/onenand/onenand_base.c |    5 +++++
>  3 files changed, 17 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
> index a3d44c3..0322388 100644
> --- a/drivers/mtd/mtdpart.c
> +++ b/drivers/mtd/mtdpart.c
> @@ -189,6 +189,7 @@ static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	return mtd_write(part->master, to + part->offset, len, retlen, buf);
>  }
>  
> +#if IS_ENABLED(CONFIG_MTD_OOPS)
>  static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
>  		size_t *retlen, const u_char *buf)
>  {
> @@ -202,6 +203,10 @@ static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	return mtd_panic_write(part->master, to + part->offset, len, retlen,
>  			       buf);
>  }
> +#else
> +#define part_panic_write	NULL
> +#endif
> +
>  
>  static int part_write_oob(struct mtd_info *mtd, loff_t to,
>  		struct mtd_oob_ops *ops)
> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 8a393f9..da8d4a6 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -753,6 +753,7 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
>   *
>   * Used when in panic, no locks are taken.
>   */
> +#if IS_ENABLED(CONFIG_MTD_OOPS)
>  static void panic_nand_get_device(struct nand_chip *chip,
>  		      struct mtd_info *mtd, int new_state)
>  {
> @@ -760,6 +761,7 @@ static void panic_nand_get_device(struct nand_chip *chip,
>  	chip->controller->active = chip;
>  	chip->state = new_state;
>  }
> +#endif
>  
>  /**
>   * nand_get_device - [GENERIC] Get chip for selected access
> @@ -2286,6 +2288,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
>   * NAND write with ECC. Used when performing writes in interrupt context, this
>   * may for example be called by mtdoops when writing an oops while in panic.
>   */
> +#if IS_ENABLED(CONFIG_MTD_OOPS)
>  static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
>  			    size_t *retlen, const uint8_t *buf)
>  {
> @@ -2315,6 +2318,10 @@ static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	*retlen = ops.retlen;
>  	return ret;
>  }
> +#else
> +#define panic_nand_write	NULL
> +#endif
> +
>  
>  /**
>   * nand_write - [MTD Interface] NAND write with ECC
> diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
> index a061bc1..9f6a2a9 100644
> --- a/drivers/mtd/onenand/onenand_base.c
> +++ b/drivers/mtd/onenand/onenand_base.c
> @@ -1736,6 +1736,7 @@ static void onenand_panic_wait(struct mtd_info *mtd)
>   *
>   * Write with ECC
>   */
> +#if IS_ENABLED(CONFIG_MTD_OOPS)

This #if should be moved up above onenand_panic_wait() which is only
used from onenand_panic_write().

Other than that, the patch looks good to me.

Ira

>  static int onenand_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
>  			 size_t *retlen, const u_char *buf)
>  {
> @@ -1819,6 +1820,10 @@ static int onenand_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
>  	*retlen = written;
>  	return ret;
>  }
> +#else
> +#define onenand_panic_write	NULL
> +#endif
> +
>  
>  /**
>   * onenand_fill_auto_oob - [INTERN] oob auto-placement transfer
> -- 
> 1.7.5.4
>

Hello Ira,

----- "Ira W. Snyder" <iws@ovro.caltech.edu> a écrit :

> On Tue, Jan 10, 2012 at 05:51:03PM +0100, Florian Fainelli wrote:
> > The mtdoops driver is the only user of the panic_write callback
> > make all panic_write related code conditionnal to CONFIG_MTD_OOPS
> > so we can save some code. Since CONFIG_MTD_OOPS can be a module
> > use the newly introduced IS_ENABLED() macro to cope with that.
> > 
> > It is safe to define the panic_write callback as NULL when
> > CONFIG_MTD_OOPS is disabled since the mtdoops drivers check for the
> > callback being non-NULL and returns an error if this the case.
> > 
> > Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
> > ---
[snip]
> > diff --git a/drivers/mtd/onenand/onenand_base.c
> b/drivers/mtd/onenand/onenand_base.c
> > index a061bc1..9f6a2a9 100644
> > --- a/drivers/mtd/onenand/onenand_base.c
> > +++ b/drivers/mtd/onenand/onenand_base.c
> > @@ -1736,6 +1736,7 @@ static void onenand_panic_wait(struct mtd_info
> *mtd)
> >   *
> >   * Write with ECC
> >   */
> > +#if IS_ENABLED(CONFIG_MTD_OOPS)
> 
> This #if should be moved up above onenand_panic_wait() which is only
> used from onenand_panic_write().

Indeed, thanks for spotting this.

> 
> Other than that, the patch looks good to me.

Thanks.
--
Florian

> 
> Ira
> 
> >  static int onenand_panic_write(struct mtd_info *mtd, loff_t to,
> size_t len,
> >  			 size_t *retlen, const u_char *buf)
> >  {
> > @@ -1819,6 +1820,10 @@ static int onenand_panic_write(struct
> mtd_info *mtd, loff_t to, size_t len,
> >  	*retlen = written;
> >  	return ret;
> >  }
> > +#else
> > +#define onenand_panic_write	NULL
> > +#endif
> > +
> >  
> >  /**
> >   * onenand_fill_auto_oob - [INTERN] oob auto-placement transfer
> > -- 
> > 1.7.5.4
> >