83xx: PCI agent mode fixes for multi-board systems

When running a system with 2 or more MPC8349EMDS boards in PCI agent mode,
the boards will lock up the PCI bus by scanning against each other.

The boards lock against each other by trying to access the PCI bus before
clearing their configuration lock bit. Both boards end up in a loop,
sending and receiving "Target Not Ready" messages forever.

When running in PCI agent mode, the scanning now takes place after the
boards have cleared their configuration lock bit.

Also, add a missing declaration to the mpc83xx.h header file, fixing a
build warning.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

diff --git a/cpu/mpc83xx/pci.c b/cpu/mpc83xx/pci.c
index ab0760bce65d584cc78cbebb79e1ab89df976a18..e9965d7df317e0dcf40520c987d42c367a2ce245 100644 (file)
--- a/cpu/mpc83xx/pci.c
+++ b/cpu/mpc83xx/pci.c
@@ -118,10 +118,12 @@ static void pci_init_bus(int bus, struct pci_region *reg)
 #ifdef CONFIG_PCI_SCAN_SHOW
        printf("PCI:   Bus Dev VenId DevId Class Int\n");
 #endif
+#ifndef CONFIG_PCISLAVE
        /*
         * Hose scan.
         */
        hose->last_busno = pci_hose_scan(hose);
+#endif
 }
 
 /*
@@ -190,6 +192,9 @@ void mpc83xx_pcislave_unlock(int bus)
        pci_hose_read_config_word (hose, dev, PCI_FUNCTION_CONFIG, &reg16);
        reg16 &= ~(PCI_FUNCTION_CFG_LOCK);
        pci_hose_write_config_word (hose, dev, PCI_FUNCTION_CONFIG, reg16);
+
+       /* The configuration bit is now unlocked, so we can scan the bus */
+       hose->last_busno = pci_hose_scan(hose);
 }
 #endif
 

diff --git a/include/mpc83xx.h b/include/mpc83xx.h
index 43553f5ae653c9516e1a2c654d7321a29c519edc..e5dfe3f21e801c6409e54b679cdd9843a451d9b0 100644 (file)
--- a/include/mpc83xx.h
+++ b/include/mpc83xx.h
@@ -1173,6 +1173,7 @@
 #ifndef __ASSEMBLY__
 struct pci_region;
 void mpc83xx_pci_init(int num_buses, struct pci_region **reg, int warmboot);
+void mpc83xx_pcislave_unlock(int bus);
 #endif
 
 #endif /* __MPC83XX_H__ */