[U-Boot] [PATCH v2] T2080QDS/PCIe: Soft Reset PCIe for down-training issue

[prabhakar at freescale.com]

Hi Zhao,


> -----Original Message-----
> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Zhao Qiang
> Sent: Wednesday, March 11, 2015 2:42 PM
> To: u-boot at lists.denx.de; Sun York-R58495
> Cc: Zhao Qiang-B45475
> Subject: [U-Boot] [PATCH v2] T2080QDS/PCIe: Soft Reset PCIe for down-training
> issue
> 
> T2080QDS PEX1/Slot#1 will down-train from x4 to x2, Soft reset PCIe can fix this
> issue, this is a workaround.
> 
> Signed-off-by: Zhao Qiang <B45475 at freescale.com>
> ---
> changes for v2
> 	- modify the commit message
> 
>  drivers/pci/fsl_pci_init.c | 17 +++++++++++++++++  include/configs/T208xQDS.h
> |  1 +
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/pci/fsl_pci_init.c b/drivers/pci/fsl_pci_init.c index
> 231b075..327fa7d 100644
> --- a/drivers/pci/fsl_pci_init.c
> +++ b/drivers/pci/fsl_pci_init.c
> @@ -481,6 +481,23 @@ void fsl_pci_init(struct pci_controller *hose, struct
> fsl_pci_info *pci_info)  #endif
>  	}
> 
> +#ifdef CONFIG_FSL_PCIE_T2080QDS_RESET
> +		int i;
> +		/* assert PCIe reset */
> +		setbits_be32(&pci->pdb_stat, 0x08000000);
> +		(void) in_be32(&pci->pdb_stat);
> +		udelay(1000);
> +		/* clear PCIe reset */
> +		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);
> +		}
> +
> +#endif
> +
>  #ifdef CONFIG_SYS_P4080_ERRATUM_PCIE_A003
>  		if (enabled == 0) {
>  			serdes_corenet_t *srds_regs = (void
> *)CONFIG_SYS_FSL_CORENET_SERDES_ADDR;
> diff --git a/include/configs/T208xQDS.h b/include/configs/T208xQDS.h index
> 395472b..851b4f9 100644
> --- a/include/configs/T208xQDS.h
> +++ b/include/configs/T208xQDS.h
> @@ -558,6 +558,7 @@ unsigned long get_board_ddr_clk(void);
>  #define CONFIG_PCIE2		/* PCIE controler 2 */
>  #define CONFIG_PCIE3		/* PCIE controler 3 */
>  #define CONFIG_PCIE4		/* PCIE controler 4 */
> +#define CONFIG_FSL_PCIE_T2080QDS_RESET

do we really require this new define?

Can we not manage with CONFIG_FSL_PCIE_RESET?

-prabhakar