[U-Boot] Why spi flash probe runs twice on Xilinx Zynq board ?

[Heshsham Abdul Basit]

 Hi,

I am re-sending this email because earlier I forgot to put the subject line
properly. I am struggling to figure out few things in u-boot , but I failed
to get a good resource or help.

This is a section of the log from u-boot running on Avnet Microzed board:


[Thu Jun 26 17:40:53.656 2014]

[Thu Jun 26 17:40:53.656 2014]

[Thu Jun 26 17:40:53.656 2014] U-Boot 2013.07 (Jun 26 2014 - 17:34:41)

[Thu Jun 26 17:40:53.656 2014]

[Thu Jun 26 17:40:53.656 2014] 1 GiB

[Thu Jun 26 17:40:53.671 2014] SF: Detected
S25FL129P_64K/S25FL128S_64K with page size 64 KiB, total 16 MiB

[Thu Jun 26 17:40:53.703 2014] *** Warning - bad CRC, using default
environment

[Thu Jun 26 17:40:53.703 2014]

[Thu Jun 26 17:40:53.703 2014] In:    serial

[Thu Jun 26 17:40:53.703 2014] Out:   serial

[Thu Jun 26 17:40:53.703 2014] Err:   serial

[Thu Jun 26 17:40:53.703 2014] U-BOOT for suheb_24

[Thu Jun 26 17:40:53.703 2014]

[Thu Jun 26 17:40:53.703 2014]

[Thu Jun 26 17:40:53.703 2014] SF: Detected
S25FL129P_64K/S25FL128S_64K with page size 64 KiB, total 16 MiB

[Thu Jun 26 17:40:54.453 2014] SF: 5242880 bytes @ 0x520000 Read: OK

[Thu Jun 26 17:40:54.453 2014]      Description:  PetaLinux Kernel

[Thu Jun 26 17:40:54.453 2014] 0x010000f0

[Thu Jun 26 17:40:54.453 2014] 4620145 Bytes = 4.4 MiB

[Thu Jun 26 17:40:54.453 2014]      Description:  Flattened Device Tree blob

[Thu Jun 26 17:40:54.453 2014] 0x01468114

[Thu Jun 26 17:40:54.453 2014] 9766 Bytes = 9.5 KiB

[Thu Jun 26 17:40:54.453 2014]      Hash algo:    crc32

[Thu Jun 26 17:40:54.453 2014]      Hash value:   9a94aca8

[Thu Jun 26 17:40:54.453 2014]      Hash algo:    sha1

[Thu Jun 26 17:40:54.453 2014]      Hash value:
97b81e3014decb706ff19e61e1227dace97d4232

[Thu Jun 26 17:40:54.453 2014] crc32+ sha1+  Uncompressing Kernel Image ...
OK

.
.I noticed that the following lines are coming twice:

SF: Detected S25FL129P_64K/S25FL128S_64K with page size 64 KiB, total 16 MiB

This corresponds to the function spi_flash_probe from
drivers/mtd/spi/spi_flash.c


I need to know:

1- Why it is probed twice?
2- The name and location of the file from where it is called (twice).
3- The second time it is being probed  is considerably slow, why it is so?


I have searched many forums and have looked in the code but still I am not
able to figure out these things.



Thanks and regards,

Abdul Basit