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 --- 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 2be192d..c938313 100644 --- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c +++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c @@ -137,6 +137,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) #ifdef CONFIG_SYS_FSL_ERRATUM_A_004934 puts("Work-around for Erratum A004934 enabled\n"); #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 03baaee..682b65d 100644 --- a/arch/powerpc/include/asm/config_mpc85xx.h +++ b/arch/powerpc/include/asm/config_mpc85xx.h @@ -417,6 +417,7 @@ #define CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV 0x20 #define CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY 0xff000000 #define CONFIG_SYS_FSL_ERRATUM_SRIO_A004034 +#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 48ae163..77ac1f7 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, &ltssm); + 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);