[U-Boot] [U-Boot PATCH v2 05/12] NAND: DaVinci: allow forced disable of subpage writes

Scott Wood scottwood at freescale.com
Thu Feb 27 20:21:47 CET 2014


On Thu, 2014-02-27 at 16:14 +0000, Karicheri, Muralidharan wrote:
> >-----Original Message-----
> >From: Scott Wood [mailto:scottwood at freescale.com]
> >Sent: Tuesday, February 25, 2014 11:01 PM
> >To: Karicheri, Muralidharan
> >Cc: u-boot at lists.denx.de; Rini, Tom
> >Subject: Re: [U-Boot] [U-Boot PATCH v2 05/12] NAND: DaVinci: allow forced disable of
> >subpage writes
> >
> >On Thu, 2014-02-20 at 12:55 -0500, Murali Karicheri wrote:
> >> This patch introduces a configurable mechanism to disable subpage
> >> writes in the DaVinci NAND driver.
> >>
> >> Signed-off-by: Vitaly Andrianov <vitalya at ti.com>
> >> Signed-off-by: Murali Karicheri <m-karicheri2 at ti.com>
> >> ---
> >>  - Added README
> >>  README                          |    5 +++++
> >>  drivers/mtd/nand/davinci_nand.c |    3 +++
> >>  2 files changed, 8 insertions(+)
> >>
> >> diff --git a/README b/README
> >> index aea82be..caf60a2 100644
> >> --- a/README
> >> +++ b/README
> >> @@ -4427,6 +4427,11 @@ Low Level (hardware related) configuration options:
> >>  - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
> >>  		Enables the RTC32K OSC on AM33xx based plattforms
> >>
> >> +- CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
> >> +		Option to disable subpage write in NAND driver
> >> +		Example driver that use this:
> >> +		drivers/mtd/nand/davinci_nand.c
> >
> >I'd rather this be a full list of drivers that use it, not an example.
> 
> There are 3 drivers out there that disable sub page write using NAND_NO_SUBPAGE_WRITE
> by default. 
> 
> nand/docg4.c
> nand/fsl_ifc_nand.c
> nand/mxs_nand.c
> 
> nand/davinci_nand.c is used across many of ti's existing davinci platforms and some of them
> do enable sub page write.

And only one of them uses CONFIG_SYS_NAND_NO_SUBPAGE_WRITE, which is a
potentially confusing thing given the generic naming, and thus warrants
clear documentation.

> In Keystone platform, we want to disable this option. So to answer
> your question, davinci_nand.c is the only user driver using this configuration option,
> but that doesn't prevent anyone from using the option. So I want to keep this configuration
> option as a generic option.

That's fine.  My point is just to s/Example driver/Drivers/ so that if
someone adds this to a new driver, they (hopefully) add it to the list
in README, rather than just thinking one example is enough.

-Scott




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