[U-Boot-Users] initialize non-transparent PCI-to-PCI bridge

hi, all I am porting U-boot to custom cpci board (MPC8540 based). On the board, we use Intel non-transparent PCI-to-PCI bridge 21555 to isolate MPC8540 from system, and MPC8540 is connected to secondary pci bus of 21555. Because no srom is connected to 21555, we configure 21555 using mpc8540 (implemented in U-boot). After system starts up, mpc8540 can find and access 21555, but system card can not find and configure it(such as BAR0, BAR1). If we delay booting of system card(boot mpc8540 firstly), system card can find and configure 21555 successfully. How to fixthe problem? Could you please give me a hand?
Best Regards, Cui

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CuiYW wrote: | hi, all | I am porting U-boot to custom cpci board (MPC8540 based). On the | board, we use Intel non-transparent PCI-to-PCI bridge 21555 to isolate | MPC8540 from system, and MPC8540 is connected to secondary pci bus of 21555.
We use that chip on our JSE board.
| Because no srom is connected to 21555, we configure 21555 using | mpc8540 (implemented in U-boot).
That's how we do it. Check out the board support files for the JSE board in the U-Boot CVS head.
After system starts up, mpc8540 can | find and access 21555, but system card can not find and configure | it(such as BAR0, BAR1). If we delay booting of system card(boot mpc8540 | firstly), system card can find and configure 21555 successfully. | How to fixthe problem? Could you please give me a hand?
The bridge should initially come up configured so that the host side configuration cycles are retried. Configure the 21555 to your liking, then clear the PCI-Lockout bit. The chip should boot up with the PCI-Lockout bit set. Otherwise, you are stuck.
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participants (2)
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CuiYW
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Stephen Williams