On Tue, Aug 06, 2019 at 05:11:17PM +0000, Stefan-gabriel Mirea wrote:

On 8/5/2019 6:31 PM, gregkh@linuxfoundation.org wrote:

quoted

On Fri, Aug 02, 2019 at 07:47:23PM +0000, Stefan-gabriel Mirea wrote:

quoted

+/* Freescale Linflex UART */
+#define PORT_LINFLEXUART     121

Do you really need this modified?

Hello Greg,

This macro is meant to be assigned to port->type in the config_port
method from uart_ops, in order for verify_port to know if the received
serial_struct structure was really targeted for a LINFlex port. It
needs to be defined outside, to avoid "collisions" with other drivers.

Yes, I know what it goes to, but does anyone in userspace actually use
it?

As far as I see, uart_set_info() will actually fail at the
"baud_base < 9600" check[1], right after calling verify_port(), when
performing an ioctl() on "/dev/console" with TIOCSSERIAL using a
serial_struct obtained with TIOCGSERIAL. This happens because this
reduced version of the LINFlex UART driver will not touch the uartclk
field of the uart_port (as there is currently no clock support).
Therefore, the linflex_config/verify_port() functions, along with the
PORT_LINFLEXUART macro, may be indeed unnecessary at this point (and
should be added later). Is this what you mean?

No, see below.

Other than that, I do not see anything wrong with the addition of a
define in serial_core.h for this purpose (which is also what most of the
serial drivers do, including amba-pl011.c, mentioned in
Documentation/driver-api/serial/driver.rst as providing the reference
implementation), so please be more specific.

I am getting tired of dealing with merge issues with that list, and no
one seems to be able to find where they are really needed for userspace,
especially for new devices.  What happens if you do not have use it?

thanks,

greg k-h

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