Re: [PATCH v3 10/10] driver/char: add RX support to the XHCI driver

[Jan Beulich <jbeulich@xxxxxxxx>]

On 05.08.2022 11:58, Marek Marczykowski-Górecki wrote:
> On Fri, Aug 05, 2022 at 10:38:13AM +0200, Jan Beulich wrote:
>> On 26.07.2022 05:23, Marek Marczykowski-Górecki wrote:
>>> @@ -454,6 +466,12 @@ static uint32_t xhci_trb_tfre_cc(const struct xhci_trb 
>>> *trb)
>>>      return trb->status >> 24;
>>>  }
>>>  
>>> +/* Amount of data _not_ transferred */
>>> +static uint32_t xhci_trb_tfre_len(const struct xhci_trb *trb)
>>> +{
>>> +    return trb->status & 0x1FFFF;
>>> +}
>>
>> Same as xhci_trb_norm_len()?
> 
> Yes, I was considering to use that, but technically those are different
> packets, only incidentally using the same bits.

I see. That's the problem with using literal numbers rather than #define-s.
But for a driver like this I didn't want to be overly picky, and hence
would have wanted to let you get away without introducing many more.

>>> @@ -985,6 +1054,33 @@ static void dbc_flush(struct dbc *dbc, struct 
>>> xhci_trb_ring *trb,
>>>  }
>>>  
>>>  /**
>>> + * Ensure DbC has a pending transfer TRB to receive data into.
>>> + *
>>> + * @param dbc the dbc to flush
>>> + * @param trb the ring for the TRBs to transfer
>>> + * @param wrk the work ring to receive data into
>>> + */
>>> +static void dbc_enqueue_in(struct dbc *dbc, struct xhci_trb_ring *trb,
>>> +                           struct dbc_work_ring *wrk)
>>
>> I can't seem to be able to spot any use of this function - it being
>> static, how do things build for you?
> 
> It's in dbc_uart_poll().

Oh, interesting. This then means that patch 1 on its own doesn't build.

Jan