drm/amdgpu: The I2C IP doesn't support 0 writes/reads

The I2C IP doesn't support writes or reads of 0 bytes.

In order for a START/STOP transaction to take
place on the bus, the data written/read has to be
at least one byte.

That is, you cannot generate a write with 0 bytes,
just to get the ACK from a device, just so you can
probe that device if it is on the bus and so to
discover all devices on the bus--you'll have to
read at least one byte. Writes of 0 bytes generate
no START/STOP on this I2C IP--the bus is not
engaged at all.

Set the I2C_AQ_NO_ZERO_LEN to the existing I2C
quirk tables for Aldebaran, Arcturus, Navi10 and
Sienna Cichlid, and add a quirk table to the I2C
driver which drives the bus when the SMU
doesn't--for instance on Vega20.

Cc: Alexander Deucher <[email protected]>
Cc: Andrey Grodzovsky <[email protected]>
Cc: Lijo Lazar <[email protected]>
Cc: John Clements <[email protected]>
Cc: Hawking Zhang <[email protected]>
Signed-off-by: Luben Tuikov <[email protected]>
Reviewed-by: Lijo Lazar <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions