On 4/23/2018 9:53 AM, S, Shirish wrote:
>
>
> On 4/20/2018 11:52 PM, Harry Wentland wrote:
>> On 2018-04-17 10:56 PM, Shirish S wrote:
>>> Currently the dm_dp_aux_transfer() does not parse
>>> the return value of dal_ddc_service_read_dpcd_data(), which also
>>> has a failure case.
>>> This patch captures the same and ensures the i2c operation status is
>>> sent appropriately to the drm framework.
>>>
>>> V2: Updated commit message.
>>>
>>> Signed-off-by: Shirish S <shirish.s at amd.com>
>>> ---
>>> Â drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 6
>>> +++++-
>>> Â 1 file changed, 5 insertions(+), 1 deletion(-)
>>>
>>> diff --git
>>> a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
>>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
>>> index 782491e..7ac124d 100644
>>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
>>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
>>> @@ -115,7 +115,11 @@ static ssize_t dm_dp_aux_transfer(struct
>>> drm_dp_aux *aux,
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â msg->address,
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â msg->buffer,
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â msg->size);
>>> -Â Â Â Â Â Â Â return read_bytes;
>>> +Â Â Â Â Â Â Â if (read_bytes != msg->size &&
>>> +Â Â Â Â Â Â Â Â Â Â Â read_bytes >= DDC_RESULT_FAILED_OPERATION)
>> This doesn't look right. We shouldn't be returning the size or error
>> code from the same function. This will not work if we submit a read 7
>> or 8 bytes and get an error.
> Agree, but hope you understood the issue, to re-iterate, in case of
> failure we reuturn a +ve number(7 or 8) back from dm_dp_aux_transfer()
> leading to edid read failures later.
> I have 2 suggestions:
> 1. change the "enum ddc_result {" to #defines of -ve error codes? or
> 2. make enum start with 129 (> than the max read_bytes possible)?
> let me know which one would be better?
Any suggestions?
> Thanks,
> Regards,
> Shirish S
>>
>> Harry
>>
>>> +Â Â Â Â Â Â Â Â Â Â Â return -EIO;
>>> +Â Â Â Â Â Â Â else
>>> +Â Â Â Â Â Â Â Â Â Â Â return read_bytes;
>>> Â Â Â Â Â case DP_AUX_I2C_WRITE:
>>> Â Â Â Â Â Â Â Â Â res = dal_ddc_service_write_dpcd_data(
>>> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â TO_DM_AUX(aux)->ddc_service,
>>>
>
