[PATCH v1] treewide, serdev: change receive_buf() return type to size_t

[Francesco Dolcini]

On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> From: Francesco Dolcini <francesco.dolcini at toradex.com>
> 
> receive_buf() is called from ttyport_receive_buf() that expects values
> ">= 0" from serdev_controller_receive_buf(), change its return type from
> ssize_t to size_t.
> 
> Suggested-by: Jiri Slaby <jirislaby at kernel.org>
> Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
> Signed-off-by: Francesco Dolcini <francesco.dolcini at toradex.com>
> ---
> hello,
> patch is based on current linux next.
> 
> It has an obvious problem, it touches files from multiple subsystem in a single
> patch that is complicated to review and eventually merge, just splitting this
> would however not work, it will break bisectability and the build.
> 
> I am looking for advise on the best way to move forward.
> 
> I see the following options:
>  - keep it as it is
>  - break it down with a patch with each subsystem, and squash before applying
>    from a single (tty?) subsystem
>  - go for a multi stage approach, defining a new callback, move to it and in
>    the end remove the original one, likewise it was done for i2c lately

whoops. I just noticed Greg applied commit 475fc6e2de6f ("tty: serdev:
convert to u8 and size_t") that touch the exact same files without much
of an issue.

Probably the "keep it as it is" is just the way to go.

> 
> ---
>  drivers/bluetooth/btmtkuart.c              |  4 ++--
>  drivers/bluetooth/btnxpuart.c              |  4 ++--
>  drivers/bluetooth/hci_serdev.c             |  4 ++--
>  drivers/gnss/core.c                        |  6 +++---
>  drivers/gnss/serial.c                      |  4 ++--
>  drivers/gnss/sirf.c                        |  6 +++---
>  drivers/greybus/gb-beagleplay.c            |  6 +++---
>  drivers/iio/chemical/pms7003.c             |  4 ++--
>  drivers/iio/chemical/scd30_serial.c        |  4 ++--
>  drivers/iio/chemical/sps30_serial.c        |  4 ++--
>  drivers/iio/imu/bno055/bno055_ser_core.c   |  4 ++--
>  drivers/mfd/rave-sp.c                      |  4 ++--
>  drivers/net/ethernet/qualcomm/qca_uart.c   |  2 +-
>  drivers/nfc/pn533/uart.c                   |  4 ++--
>  drivers/nfc/s3fwrn5/uart.c                 |  4 ++--
>  drivers/platform/chrome/cros_ec_uart.c     |  4 ++--
>  drivers/platform/surface/aggregator/core.c |  4 ++--
>  drivers/tty/serdev/serdev-ttyport.c        | 10 ++++------
>  include/linux/gnss.h                       |  4 ++--
>  include/linux/serdev.h                     |  8 ++++----
>  sound/drivers/serial-generic.c             |  4 ++--
>  21 files changed, 48 insertions(+), 50 deletions(-)