Re: [PATCH] i3c: don't fail if GETHDRCAP is unsupported

Joshua Yeong
2025-06-26T03:05:25Z

On 25-Jun-2025 11:24 PM, Frank Li wrote:
> On Wed, Jun 25, 2025 at 09:34:52AM +0200, Wolfram Sang wrote:
>> If a target has the HDR_CAP bit set in BCR, the core wants to get
>> additional information using the CCC 'GETHDRCAP'. Not all controllers
>> support this CCC, though.
>
> Do you know which target device support HDR? I3C master API don't HDR yet.
>
>> This is not fatal. We can just skip it. The
>> information is not needed if the controller won't support HDR anyhow.
>
> This is not fatal and can be safely skipped, as the information is not
> necessary if HDR is unsupported by the controller anyway.
>
> Frank

Hi Frank

I'm use `MMC5633` to test out the HDR-DDR functionality master functionality.
The patch can be accepted as some controller might not support HDR.

>>
>> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
>> ---
>>
>> Found during the I3C plugfest in Warsaw.
>>
>> drivers/i3c/master.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
>> index 204b96e6be1e..b6b96cf9e4e0 100644
>> --- a/drivers/i3c/master.c
>> +++ b/drivers/i3c/master.c
>> @@ -1440,7 +1440,7 @@ static int i3c_master_retrieve_dev_info(struct i3c_dev_desc *dev)
>>
>> if (dev->info.bcr & I3C_BCR_HDR_CAP) {
>> ret = i3c_master_gethdrcap_locked(master, &dev->info);
>> - if (ret)
>> + if (ret && ret != -ENOTSUPP)
>> return ret;
>> }
>>
>> --
>> 2.47.2
>>
>>
>> --
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