Re: [PATCH v5 3/3] tty: serial: qcom_geni_serial: Remove sysfs file

[Akash Asthana <akashast@codeaurora.org>]

On 11/16/2019 1:15 AM, Stephen Boyd wrote:
> Quoting Akash Asthana (2019-11-15 01:57:48)
>> On 11/14/2019 11:06 PM, Stephen Boyd wrote:
>>> Please update the subject. This patch does more than remove the sysfs
>>> file. "Move loopback support to TIOCM_LOOP"?
>> Ok, I will update this in next version.
>>> Quoting Akash Asthana (2019-11-13 02:49:21)
>>>> Remove code from the driver that create and maintain loopback sysfs node.
>>>> Instead use the ioctl TIOCMSET with TIOCM_LOOP argument to set HW to
>>>> loopback mode.
>>>>
>>>> Signed-off-by: Akash Asthana <akashast@codeaurora.org>
>>>> ---
>>>> Changes in V5:
>>>>    - As per Greg's and Stephen's comment on v4 patch, removed loopback sysfs
>>>>      file related code.
>>>>
>>>>    drivers/tty/serial/qcom_geni_serial.c | 30 ++++--------------------------
>>>>    1 file changed, 4 insertions(+), 26 deletions(-)
>>>>
>>>> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
>>>> index 56dad67..52f5ea2 100644
>>>> --- a/drivers/tty/serial/qcom_geni_serial.c
>>>> +++ b/drivers/tty/serial/qcom_geni_serial.c
>>>> @@ -238,10 +214,14 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>>>>                                                           unsigned int mctrl)
>>>>    {
>>>>           u32 uart_manual_rfr = 0;
>>>> +       struct qcom_geni_serial_port *port = to_dev_port(uport, uport);
>>>>    
>>>>           if (uart_console(uport))
>>>>                   return;
>>>>    
>>>> +       if (mctrl & TIOCM_LOOP)
>>>> +               port->loopback = MAX_LOOPBACK_CFG;
>>> How does this work? The loopback is supposed to be the max all the time
>>> and not match some qup number or something?
>> port->loopback is unrelated to QUP number. However we have different
>> modes to run loopback test, 1(rx-tx sorted), 2(cts-rts sorted),
>>
>> 3 or Max(rx-tx sorted and cts-rts sorted). In our internal testing we
>> only use mode 3 hence we are initializing port->loopback variable
>>
>> to 3 and eventually it will be written to HW register from set_termios
>> call.
> Ok. Thanks for clarifying. Can you rename this macro to
> RX_TX_CTS_RTS_SORTED? I imagine seeing something like:
>
> 	/* SE_UART_LOOPBACK_CFG */
> 	#define RX_TX_SORTED		BIT(0)
> 	#define CTS_RTS_SORTED		BIT(1)
> 	#define RX_TX_CTS_RTS_SORTED	RX_TX_SORTED | CTS_RTS_SORTED
>
> or whatever the bit field names really are.
Ok, I will update this is v6.

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