Commit d2740f7d authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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tty: serial: extract uart_change_port() from uart_set_info() 



This "change_port" part of uart_set_info() is for no good reason
inlined there. It makes the function rather hard to read. Therefore,
extract it to a separate function.

This allows for flattening the ifs (with short path "return"s) and
avoiding two levels of indentation. Both making the code really flat and
comprehesible.

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20241211074933.92973-4-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4d0e56d5

drivers/tty/serial/serial_core.c

+58 −56
Original line number Diff line number Diff line
@@ -834,6 +834,61 @@ static int uart_get_info_user(struct tty_struct *tty, 
	return uart_get_info(port, ss) < 0 ? -EIO : 0;

}



static int uart_change_port(struct uart_port *uport,

			    const struct serial_struct *new_info,

			    unsigned long new_port)

{

	unsigned long old_iobase, old_mapbase;

	unsigned int old_type, old_iotype, old_hub6, old_shift;

	int retval;



	old_iobase = uport->iobase;

	old_mapbase = uport->mapbase;

	old_type = uport->type;

	old_hub6 = uport->hub6;

	old_iotype = uport->iotype;

	old_shift = uport->regshift;



	if (old_type != PORT_UNKNOWN && uport->ops->release_port)

		uport->ops->release_port(uport);



	uport->iobase = new_port;

	uport->type = new_info->type;

	uport->hub6 = new_info->hub6;

	uport->iotype = new_info->io_type;

	uport->regshift = new_info->iomem_reg_shift;

	uport->mapbase = (unsigned long)new_info->iomem_base;



	if (uport->type == PORT_UNKNOWN || !uport->ops->request_port)

		return 0;



	retval = uport->ops->request_port(uport);

	if (retval == 0)

		return 0; /* succeeded => done */



	/*

	 * If we fail to request resources for the new port, try to restore the

	 * old settings.

	 */

	uport->iobase = old_iobase;

	uport->type = old_type;

	uport->hub6 = old_hub6;

	uport->iotype = old_iotype;

	uport->regshift = old_shift;

	uport->mapbase = old_mapbase;



	if (old_type == PORT_UNKNOWN)

		return retval;



	retval = uport->ops->request_port(uport);

	/* If we failed to restore the old settings, we fail like this. */

	if (retval)

		uport->type = PORT_UNKNOWN;



	/* We failed anyway. */

	return -EBUSY;

}



static int uart_set_info(struct tty_struct *tty, struct tty_port *port,

			 struct uart_state *state,

			 struct serial_struct *new_info)
@@ -930,63 +985,10 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 
	}



	if (change_port) {

		unsigned long old_iobase, old_mapbase;

		unsigned int old_type, old_iotype, old_hub6, old_shift;



		old_iobase = uport->iobase;

		old_mapbase = uport->mapbase;

		old_type = uport->type;

		old_hub6 = uport->hub6;

		old_iotype = uport->iotype;

		old_shift = uport->regshift;



		/*

		 * Free and release old regions

		 */

		if (old_type != PORT_UNKNOWN && uport->ops->release_port)

			uport->ops->release_port(uport);



		uport->iobase = new_port;

		uport->type = new_info->type;

		uport->hub6 = new_info->hub6;

		uport->iotype = new_info->io_type;

		uport->regshift = new_info->iomem_reg_shift;

		uport->mapbase = (unsigned long)new_info->iomem_base;



		/*

		 * Claim and map the new regions

		 */

		if (uport->type != PORT_UNKNOWN && uport->ops->request_port) {

			retval = uport->ops->request_port(uport);

			/*

			 * If we fail to request resources for the

			 * new port, try to restore the old settings.

			 */

			if (retval) {

				uport->iobase = old_iobase;

				uport->type = old_type;

				uport->hub6 = old_hub6;

				uport->iotype = old_iotype;

				uport->regshift = old_shift;

				uport->mapbase = old_mapbase;



				if (old_type != PORT_UNKNOWN) {

					retval = uport->ops->request_port(uport);

					/*

					 * If we failed to restore the old

					 * settings, we fail like this.

					 */

		retval = uart_change_port(uport, new_info, new_port);

		if (retval)

						uport->type = PORT_UNKNOWN;



					/* We failed anyway. */

					return -EBUSY;

				}



			return retval;

	}

		}

	}



	if (change_irq)

		uport->irq      = new_info->irq;