[U-Boot] [PATCH v3 19/20] configs: Don't use SPI_FLASH_BAR as default

[Vignesh R]

On 31/01/19 7:20 PM, Jagan Teki wrote:
> On Thu, 31 Jan, 2019, 7:16 PM Vignesh R <vigneshr at ti.com
> <mailto:vigneshr at ti.com> wrote:
> 
>     On 31/01/19 7:06 PM, Jagan Teki wrote:
>     [...]
>     >     >>  configs/xilinx_zynqmp_mini_qspi_defconfig        | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1232_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1254_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1275_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1275_revB_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1751_xm016_dc2_defconfig | 1 -
>     >     >>  configs/xilinx_zynqmp_zc1751_xm018_dc4_defconfig | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu100_revC_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu102_rev1_0_defconfig    | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu102_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu102_revB_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu104_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu104_revC_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu106_revA_defconfig      | 1 -
>     >     >>  configs/xilinx_zynqmp_zcu111_revA_defconfig      | 1 -
>     >     >>  configs/zynq_cc108_defconfig                     | 1 -
>     >     >>  configs/zynq_cse_qspi_defconfig                  | 1 -
>     >     >>  configs/zynq_dlc20_rev1_0_defconfig              | 1 -
>     >     >>  configs/zynq_microzed_defconfig                  | 1 -
>     >     >>  configs/zynq_minized_defconfig                   | 1 -
>     >     >>  configs/zynq_z_turn_defconfig                    | 1 -
>     >     >>  configs/zynq_zc702_defconfig                     | 1 -
>     >     >>  configs/zynq_zc706_defconfig                     | 1 -
>     >     >>  configs/zynq_zc770_xm010_defconfig               | 1 -
>     >     >>  configs/zynq_zc770_xm013_defconfig               | 1 -
>     >     >>  configs/zynq_zed_defconfig                       | 1 -
>     >     >>  configs/zynq_zybo_defconfig                      | 1 -
>     >     >>  configs/zynq_zybo_z7_defconfig                   | 1 -
>     >     >
>     >     > zynq targets do need BAR, same has commented in previous mails.
>     >
>     >     Hmmm, Is this a  limitation of SPI controller on the SoC or
>     flash on the
>     >     board?
>     >     AFAICS, zynq_spi.c, zynq_qspi.c zynq_spi.c zynqmp_gqspi.c are
>     all FIFO
>     >     based SPI controllers and ideally should not care about
>     address length.
>     >     Could you please explain why BAR is a requirement on these
>     platforms?
>     >
>     >     Were you able to test this series on any of those platforms?
>     >
>     >
>     > Go back to the log history, initial intension for adding BAR was
>     on zynq.
>     >
> 
> 
>     Sorry, this is all I could find from mailing list (original series by
>     you that adds BAR support):
>     https://lists.denx.de/pipermail/u-boot/2013-June/157006.html
> 
>     There is nothing that mentions why Zynq platforms need BAR support and
>     cannot use 4 byte opcodes to access >16MB space?
> 
> 
> Yes, zynq qspi ia unable to handle larger than 16MiB flashes so we used
> BAR to access those.
> 

I wonder how those boards work in kernel that does not support BAR.
Anyways, if you provide a list of SPI controllers on zynq SoCs, I will
add an  imply SPI_FLASH_BAR for such Kconfigs and send a separate patch.

> Michal, Siva: can you confirm?
> 
> 



-- 
Regards
Vignesh