Hi Jan,
On 9/10/20 9:34 AM, Jan Kiszka wrote:
> On 10.09.20 18:31, Guenter Roeck wrote:
>> On Family 17h (Ryzen) devices, the WatchdogTmrEn bit of PmDecodeEn not only
>> enables watchdog memory decoding at 0xfeb00000, it also enables the
>> watchdog hardware itself. Use this information to enable the watchdog if
>> it is not already enabled.
>>
>> Cc: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
>> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>> ---
>> drivers/watchdog/sp5100_tco.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>> diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c
>> index 85e9664318c9..a730ecbf78cd 100644
>> --- a/drivers/watchdog/sp5100_tco.c
>> +++ b/drivers/watchdog/sp5100_tco.c
>> @@ -17,6 +17,12 @@
>> * AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
>> * AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
>> * for AMD Family 16h Models 30h-3Fh Processors"
>> + * AMD Publication 55570-B1-PUB "Processor Programming Reference (PPR)
>> + * for AMD Family 17h Model 18h, Revision B1
>> + * Processors (PUB)
>> + * AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
>> + * for AMD Family 17h Model 20h, Revision A1
>> + * Processors (PUB)
>> */
>>
>> /*
>> @@ -241,6 +247,18 @@ static int sp5100_tco_setupdevice(struct device *dev,
>> break;
>> case efch:
>> dev_name = SB800_DEVNAME;
>> + /*
>> + * On Family 17h devices, the EFCH_PM_DECODEEN_WDT_TMREN bit of
>> + * EFCH_PM_DECODEEN not only enables the EFCH_PM_WDT_ADDR memory
>> + * region, it also enables the watchdog itself.
>> + */
>> + if (boot_cpu_data.x86 == 0x17) {
>> + val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
>> + if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
>> + sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN, 0xff,
>> + EFCH_PM_DECODEEN_WDT_TMREN);
>> + }
>> + }
>> val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
>> if (val & EFCH_PM_DECODEEN_WDT_TMREN)
>> mmio_addr = EFCH_PM_WDT_ADDR;
>>
>
> Won't that bring us EFCH_PM_WDT_ADDR as address, rather than
> EFCH_PM_ACPI_MMIO_ADDR which worked in my case? Or is one an alias of
> the other.
>
Yes, it does use EFCH_PM_WDT_ADDR. EFCH_PM_ACPI_MMIO_ADDR works as well,
but is meant to be a fallback. Both point to the watchdog memory space.
Thanks,
Guenter
