From c0a4e6b889a702cc2c8375619ce7b093f6b3b1de Mon Sep 17 00:00:00 2001
From: Yuanquan Chen <B41889@freescale.com>
Date: Mon, 26 Nov 2012 23:49:45 +0000
Subject: [PATCH] powerpc/p4080ds: fix PCI-e x8 link training down failure
Due to SerDes configuration error, if we set the PCI-e controller link width
as x8 in RCW and add a narrower width(such as x4, x2 or x1) PCI-e device to
PCI-e slot, it fails to train down to the PCI-e device's link width. According
to p4080ds errata PCIe-A003, we reset the PCI-e controller link width to x4 in
u-boot. Then it can train down to x2 or x1 width to make the PCI-e link between
RC and EP.
Signed-off-by: Yuanquan Chen <B41889@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
---
arch/powerpc/cpu/mpc85xx/cmd_errata.c | 3 +++
arch/powerpc/include/asm/config_mpc85xx.h | 1 +
drivers/pci/fsl_pci_init.c | 22 ++++++++++++++++++++++
3 files changed, 26 insertions(+)
diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
index 7d38e1c3a9..e5ecf5dae5 100644
--- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
+++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
@@ -247,6 +247,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
#ifdef CONFIG_SYS_FSL_ERRATUM_A004580
/* This work-around is implemented in PBI, so just check for it */
check_erratum_a4580(svr);
+#endif
+#ifdef CONFIG_SYS_P4080_ERRATUM_PCIE_A003
+ puts("Work-around for Erratum PCIe-A003 enabled\n");
#endif
return 0;
}
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index 965d4312c7..0b9638bcee 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -421,6 +421,7 @@
#define CONFIG_SYS_FSL_ERRATUM_SRIO_A004034
#define CONFIG_SYS_FSL_ERRATUM_A004849
#define CONFIG_SYS_FSL_ERRATUM_A004580
+#define CONFIG_SYS_P4080_ERRATUM_PCIE_A003
#elif defined(CONFIG_PPC_P5020) /* also supports P5010 */
#define CONFIG_SYS_PPC64 /* 64-bit core */
diff --git a/drivers/pci/fsl_pci_init.c b/drivers/pci/fsl_pci_init.c
index 48ae16374d..77ac1f7c7b 100644
--- a/drivers/pci/fsl_pci_init.c
+++ b/drivers/pci/fsl_pci_init.c
@@ -470,6 +470,28 @@ void fsl_pci_init(struct pci_controller *hose, struct fsl_pci_info *pci_info)
}
#endif
+#ifdef CONFIG_SYS_P4080_ERRATUM_PCIE_A003
+ if (enabled == 0) {
+ serdes_corenet_t *srds_regs = (void *)CONFIG_SYS_FSL_CORENET_SERDES_ADDR;
+ temp32 = in_be32(&srds_regs->srdspccr0);
+
+ if ((temp32 >> 28) == 3) {
+ int i;
+
+ out_be32(&srds_regs->srdspccr0, 2 << 28);
+ setbits_be32(&pci->pdb_stat, 0x08000000);
+ in_be32(&pci->pdb_stat);
+ udelay(100);
+ clrbits_be32(&pci->pdb_stat, 0x08000000);
+ asm("sync;isync");
+ for (i=0; i < 100 && ltssm < PCI_LTSSM_L0; i++) {
+ pci_hose_read_config_word(hose, dev, PCI_LTSSM, <ssm);
+ udelay(1000);
+ }
+ enabled = ltssm >= PCI_LTSSM_L0;
+ }
+ }
+#endif
if (!enabled) {
/* Let the user know there's no PCIe link */
printf("no link, regs @ 0x%lx\n", pci_info->regs);
--
2.39.5