[U-Boot] [PATCH v3 075/108] x86: spi: Don't enable SPI_FLASH_BAR by default

[Simon Glass]

Hi Vignesh,

On Tue, 19 Nov 2019 at 22:21, Vignesh Raghavendra <vigneshr at ti.com> wrote:
>
> Hi,
>
> On 19/11/19 7:03 PM, Bin Meng wrote:
> > +Vignesh
> >
> > On Mon, Oct 21, 2019 at 11:40 AM Simon Glass <sjg at chromium.org> wrote:
> >>
> >> We don't normally need this on x86 unless the size of SPI flash devices is
> >> larger than 16MB. This can be enabled by particular SoCs as needed, since
> >> it adds to code size.
> >>
> >> Drop the default enabling of this option on x86.
> >>
> >> Signed-off-by: Simon Glass <sjg at chromium.org>
> >> ---
> >>
> >> Changes in v3: None
> >> Changes in v2: None
> >>
> >>  drivers/spi/Kconfig | 1 -
> >>  1 file changed, 1 deletion(-)
> >>
> >> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> >> index b8ca2bdedd5..320baeeb3eb 100644
> >> --- a/drivers/spi/Kconfig
> >> +++ b/drivers/spi/Kconfig
> >> @@ -125,7 +125,6 @@ config FSL_DSPI
> >>
> >>  config ICH_SPI
> >>         bool "Intel ICH SPI driver"
> >> -       imply SPI_FLASH_BAR
> >
> > This was added via:
> >
> > commit 6d82517836418f984b7b4c05cf1427d7b49b1169
> > Author: Vignesh R <vigneshr at ti.com>
> > Date:   Tue Feb 5 11:29:28 2019 +0530
> >
> >     configs: Don't use SPI_FLASH_BAR as default
> >
> >     Now that new SPI NOR layer uses stateless 4 byte opcodes by default,
> >     don't enable SPI_FLASH_BAR. For SPI controllers that cannot support
> >     4-byte addressing, (stm32_qspi.c, fsl_qspi.c, mtk_qspi.c, ich.c,
> >     renesas_rpc_spi.c) add an imply clause to enable SPI_FLASH_BAR so as to
> >     not break functionality.
> >
> > The commit message says: SPI_FLASH_BAR was added so as to not break
> > functionality.
> >
>
> At the time of introducing new SPI NOR layer, I found that (by code
> inspection) ich.c did  not support 4 byte addressing. Hence, "imply
> SPI_FLASH_BAR" was added for ich.c driver.
> But if driver has been improved to support 4 byte addressing or if there
> is no plan to support flashes > 16MiB by default, then it should be okay
> to remove SPI_FLASH_BAR.

Well the problem is that it adds almost 3KB to the code size in TPL,
so I think we need the option to turn it off.

Also current platforms supported in U-Boot don't have more than 8 or
16MB of SPI flash, so this should be safe.

>
> > I don't have board to test right now. Vignesh could you please have a
> > review? Thanks!
> >
> >>         help
> >>           Enable the Intel ICH SPI driver. This driver can be used to
> >>           access the SPI NOR flash on platforms embedding this Intel
> >> --

Regards,
Simon