Re: [PATCH v4 1/3] i3c: master: dw: Report actual GET CCC payload length on success

[NG, TZE YEE]

On 1/7/2026 1:03 am, Frank Li wrote:
> On Tue, Jun 30, 2026 at 06:20:25AM -0700, tze.yee.ng@xxxxxxxxxx wrote:
>> From: Adrian Ng Ho Yin <adrian.ho.yin.ng@xxxxxxxxxx>
>>
>> On successful GET CCC transfers, set dests[0].payload.actual_len from
>> RESPONSE_PORT_DATA_LEN so the I3C core receives the number of bytes
>> actually read. Add actual_len to struct i3c_ccc_cmd_payload to keep
>> the requested buffer size in len.
>>
>> Signed-off-by: Adrian Ng Ho Yin <adrian.ho.yin.ng@xxxxxxxxxx>
>> Signed-off-by: Tze Yee Ng <tze.yee.ng@xxxxxxxxxx>
>> ---
>>   drivers/i3c/master/dw-i3c-master.c | 5 ++++-
>>   include/linux/i3c/ccc.h            | 4 +++-
> 
> Can you split into two patches, first patch just add actual_len in ccc.h
> 
> Frank
> 

Sure, I will fix it in v5.

Thanks,
Tze Yee

>>   2 files changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
>> index 655693a2187e..856961da1827 100644
>> --- a/drivers/i3c/master/dw-i3c-master.c
>> +++ b/drivers/i3c/master/dw-i3c-master.c
>> @@ -742,7 +742,10 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
>>   		dw_i3c_master_dequeue_xfer(master, xfer);
>>
>>   	ret = xfer->ret;
>> -	if (xfer->cmds[0].error == RESPONSE_ERROR_IBA_NACK)
>> +	cmd = &xfer->cmds[0];
>> +	if (!ret)
>> +		ccc->dests[0].payload.actual_len = cmd->rx_len;
>> +	if (cmd->error == RESPONSE_ERROR_IBA_NACK)
>>   		ccc->err = I3C_ERROR_M2;
>>
>>   	return ret;
>> diff --git a/include/linux/i3c/ccc.h b/include/linux/i3c/ccc.h
>> index ad59a4ae60d1..d8052949e57e 100644
>> --- a/include/linux/i3c/ccc.h
>> +++ b/include/linux/i3c/ccc.h
>> @@ -343,11 +343,13 @@ struct i3c_ccc_getxtime {
>>   /**
>>    * struct i3c_ccc_cmd_payload - CCC payload
>>    *
>> - * @len: payload length
>> + * @len: requested payload length
>> + * @actual_len: number of bytes received on a GET CCC (filled by the driver)
>>    * @data: payload data. This buffer must be DMA-able
>>    */
>>   struct i3c_ccc_cmd_payload {
>>   	u16 len;
>> +	u16 actual_len;
>>   	void *data;
>>   };
>>
>> --
>> 2.43.7
>>