Re: [PATCH v4 8/8] serial: qcom-geni: Rework TX in FIFO mode to fix hangs/lockups

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 6/17/24 21:37, Doug Anderson wrote:
> Hi,
> 
> On Mon, Jun 17, 2024 at 12:10 PM Konrad Dybcio <konrad.dybcio@linaro.org> wrote:
>>
>>
>>
>> On 6/11/24 00:24, Douglas Anderson wrote:
>>> The fact that the Qualcomm GENI hardware interface is based around
>>> "packets" is really awkward to fit into Linux's UART design.
>>> Specifically, in order to send bytes you need to start up a new
>>> "command" saying how many bytes you want to send and then you need to
>>> send all those bytes. Once you've committed to sending that number of
>>> bytes it's very awkward to change your mind and send fewer, especially
>>> if you want to do so without dropping bytes on the ground.
>>
>> [...]
>>
>>
>>> +static void qcom_geni_serial_enable_cmd_done(struct uart_port *uport)
>>> +{
>>> +     struct qcom_geni_serial_port *port = to_dev_port(uport);
>>> +
>>> +     /* If we're not in FIFO mode we don't use CMD_DONE. */
>>> +     if (port->dev_data->mode != GENI_SE_FIFO)
>>> +             return;
>>> +
>>> +     writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_EN_SET);
>>> +}
>>
>> IDK if this is worth of a separate function, instead of checking for the
>> FIFO in port_setup and writing it there, but generally this patch looks
>> good to me
> 
> Sure. Somehow it felt weird to me to put it straight in there, but I
> could go either way. Do you think I should spin the series just for
> this, or just make this change if I happen to need to spin the series
> for something else?

The latter.

Konrad