[U-Boot] [PATCH v4 1/6] nand: Try to align the default buffers

[Marek Vasut]

Dear Tom Warren,

> Marek,
> 
> > -----Original Message-----
> > From: Marek Vasut [mailto:marex at denx.de]
> > Sent: Friday, September 07, 2012 11:43 AM
> > To: u-boot at lists.denx.de
> > Cc: Tom Warren; Simon Glass; Scott Wood
> > Subject: Re: [U-Boot] [PATCH v4 1/6] nand: Try to align the default
> > buffers
> > 
> > Dear Tom Warren,
> > 
> > > Simon,
> > > 
> > > > -----Original Message-----
> > > > From: Simon Glass [mailto:sjg at chromium.org]
> > > > Sent: Sunday, July 29, 2012 11:53 PM
> > > > To: U-Boot Mailing List
> > > > Cc: Tom Warren; Stephen Warren; Scott Wood; Simon Glass
> > > > Subject: [PATCH v4 1/6] nand: Try to align the default buffers
> > > > 
> > > > The NAND layer needs to use cache-aligned buffers by default.
> > > > Towards this goal. align the default buffers and their members
> > > > according to the minimum DMA alignment defined for the architecture.
> > > > 
> > > > Signed-off-by: Simon Glass <sjg at chromium.org>
> > > > ---
> > > > Changes in v2:
> > > > - Add new patch to align default buffers in nand_base
> > > > 
> > > >  drivers/mtd/nand/nand_base.c |    3 ++-
> > > >  include/linux/mtd/nand.h     |    7 ++++---
> > > >  2 files changed, 6 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/mtd/nand/nand_base.c
> > > > b/drivers/mtd/nand/nand_base.c index bfd668f..891af1f 100644
> > > > --- a/drivers/mtd/nand/nand_base.c
> > > > +++ b/drivers/mtd/nand/nand_base.c
> > > > @@ -2936,7 +2936,8 @@ int nand_scan_tail(struct mtd_info *mtd)
> > > > 
> > > >  	struct nand_chip *chip = mtd->priv;
> > > >  	
> > > >  	if (!(chip->options & NAND_OWN_BUFFERS))
> > > > 
> > > > -		chip->buffers = kmalloc(sizeof(*chip->buffers), 
GFP_KERNEL);
> > > > +		chip->buffers = memalign(ARCH_DMA_MINALIGN,
> > > > +					 sizeof(*chip->buffers));
> > > > 
> > > >  	if (!chip->buffers)
> > > >  	
> > > >  		return -ENOMEM;
> > > > 
> > > > diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
> > > > index
> > > > 82704de..dc839e7 100644
> > > > --- a/include/linux/mtd/nand.h
> > > > +++ b/include/linux/mtd/nand.h
> > > > @@ -391,9 +391,10 @@ struct nand_ecc_ctrl {
> > > > 
> > > >   * consecutive order.
> > > >   */
> > > >  
> > > >  struct nand_buffers {
> > > > 
> > > > -	uint8_t	ecccalc[NAND_MAX_OOBSIZE];
> > > > -	uint8_t	ecccode[NAND_MAX_OOBSIZE];
> > > > -	uint8_t databuf[NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE];
> > > > +	uint8_t	ecccalc[ALIGN(NAND_MAX_OOBSIZE, ARCH_DMA_MINALIGN)];
> > > > +	uint8_t	ecccode[ALIGN(NAND_MAX_OOBSIZE, ARCH_DMA_MINALIGN)];
> > > > +	uint8_t databuf[ALIGN(NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE,
> > > > +			      ARCH_DMA_MINALIGN)];
> > > > 
> > > >  };
> > 
> > include asm/cache.h or something ?
> 
> Thanks, Marek. Mxs_nand.c appears to be 99% yours (and you're listed as the
> maintainer of m28evk) - would you be willing to submit a patch? That'll
> also fix apx4devkit, which fails w/the same errors.

I think it's simple enough, just mising one common define. Generate the patch 
and I'll ack it :)

> Tom

[...]

Best regards,
Marek Vasut