[U-Boot] [PATCH] mvebu: a38x: Force receiver detected on PCIe lanes

[Stefan Roese]

On 28.05.2018 15:15, Mario Six wrote:
> Hi Stefan,
> 
> On Mon, May 28, 2018 at 2:52 PM, Stefan Roese <sr at denx.de> wrote:
>> (Added Mario and Chris)
>>
>>
>> On 27.05.2018 17:34, Baruch Siach wrote:
>>>
>>> From: Rabeeh Khoury <rabeeh at solid-run.com>
>>>
>>> Some QCA988x based modules presence is not detected by the SERDES lanes,
>>> so force this detection which will trigger the LTSSM state machine to
>>> negotiate link.
>>>
>>> An example of such a card is WLE900VX.
>>>
>>> Signed-off-by: Rabeeh Khoury <rabeeh at solid-run.com>
>>> Signed-off-by: Baruch Siach <baruch at tkos.co.il>
>>> ---
>>>    arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c | 2 ++
>>>    arch/arm/mach-mvebu/serdes/a38x/sys_env_lib.h         | 1 +
>>>    2 files changed, 3 insertions(+)
>>>
>>> diff --git a/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
>>> b/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
>>> index 13553cf96008..33e70569bc48 100644
>>> --- a/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
>>> +++ b/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
>>> @@ -597,6 +597,8 @@ struct op_params
>>> pex_electrical_config_serdes_rev2_params[] = {
>>>          {LANE_CFG4_REG, 0x800, 0x8, {0x8}, 0, 0},
>>>          /* tximpcal_th and rximpcal_th */
>>>          {VTHIMPCAL_CTRL_REG, 0x800, 0xff00, {0x3000}, 0, 0},
>>> +       /* Force receiver detected */
>>> +       {LANE_CFG0_REG, 0x800, 0x8000, {0x8000}, 0, 0},
>>>    };
>>>      /* PEX - configuration seq for REF_CLOCK_25MHz */
>>> diff --git a/arch/arm/mach-mvebu/serdes/a38x/sys_env_lib.h
>>> b/arch/arm/mach-mvebu/serdes/a38x/sys_env_lib.h
>>> index 953445b7d7ae..50b235826659 100644
>>> --- a/arch/arm/mach-mvebu/serdes/a38x/sys_env_lib.h
>>> +++ b/arch/arm/mach-mvebu/serdes/a38x/sys_env_lib.h
>>> @@ -71,6 +71,7 @@
>>>    #define RX_REG3                               0xa0188
>>>    #define PCIE_REG1                     0xa0288
>>>    #define PCIE_REG3                     0xa0290
>>> +#define LANE_CFG0_REG                  0xa0600
>>>    #define LANE_CFG1_REG                 0xa0604
>>>    #define LANE_CFG4_REG                 0xa0620
>>>    #define LANE_CFG5_REG                 0xa0624
>>>
>>
>> I understand that this might fix an issue on a specific board (ClearFog
>> in this case, correct?). But are you sure that its safe to force this
>> link detection for all A38x boards?
>>
> 
> I just did a quick test on a controlcenterdc board, and it seems to work. I'll
> try to do some more extensive tests this week (unless somebody has another
> objection, of course).

Thanks Mario, please send a "Tested-by" tag to this thread, so that
we can collect this into the patch summary.

Thanks,
Stefan