10Kz I2c speed.

[edpil02]

I just bought a RX4070 Super Ti.
Unfortunately the funny manufacturer put on the i2c bus a controller
that runs at 10kz instead of the standard 100kz , so reading and writing always fails.
I know that nvapi can change the bus speed but the necessary function is not in libnvidia-api.
Is there another way to manage the i2c bus speed for a driver.
Thanks.

[aritger]

I don't have experience with it, but if you want to hack on the nvidia.ko source, it looks like you could specify the speed in NV402C_CTRL_I2C_TRANSACTION_PARAMS::flags field in src/nvidia/arch/nvalloc/unix/src/osapi.c:RmNonDPAuxI2CTransfer().

I think add a line like:

params->flags = DRF_DEF(402C_CTRL, _I2C_FLAGS, _SPEED_MODE, _10KHZ);

or:

params->flags = DRF_DEF(402C_CTRL, _I2C_FLAGS, _SPEED_MODE, _DEFAULT);

The speeds are defined in src/common/sdk/nvidia/inc/ctrl/ctrl402c.h.
Annoyingly, the zero value is not _DEFAULT, but _100KHZ:

#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_100KHZ                                 (0x00000000)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_200KHZ                                 (0x00000001)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_400KHZ                                 (0x00000002)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_33KHZ                                  (0x00000003)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_10KHZ                                  (0x00000004)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_3KHZ                                   (0x00000005)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_DEFAULT                                (0x00000006)
#define NV402C_CTRL_I2C_FLAGS_SPEED_MODE_300KHZ                                 (0x00000007)

It is probably a bug that the driver doesn't use DEFAULT today.

Let me know if that helps.