[U-Boot] The purpose of enabling CONFIG_PCI_BOOTDELAY

Mike.Johnson at apc.com Mike.Johnson at apc.com
Wed Mar 24 21:49:02 CET 2010




All,

What is the purpose of CONFIG_PCI_BOOTDELAY? I am using uboot version
1.1.4. I know it's old, but in \drivers\pci.c there is a section of code
right before pci_init.c is called
that can delay the call to pci_init.c.

The code is enabled by defining CONFIG_PCI_BOOTDELAY. But why would it be
necessary to delay initializing the PCI hardware?

Specifically in my case, all the resets on my board have occurred well
before (500 msec) this portion of the code would execute, so it would seem
safe to say that any peripherals like PCI controllers would be satisfied
reset-wise.

In my case though, I need to enable CONFIG_PCI_BOOTDELAY to eliminate a WDT
problem with a PCI access.

If I do not use CONFIG_PCI_BOOTDELAY, my hardware can exhibit a PCI hang,
leading to the above mentioned WDT.

Any information or background that this group can provide would be
appreciated.

Thank-you,

Mike

Michael Johnson
American Power Conversion
132 Fairgrounds Road
West Kingston, RI  02892
tele: (401) 789 - 5735 x2982



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