kernel/linux.git/drivers/tty/tty_buffer.c, branch v6.6.132

tty: tty_buffer: invert conditions in __tty_buffer_request_room()

2023-08-22T12:58:16+00:00

We are used to handle "bad" states in the 'if's in the kernel. Refactor (invert the two conditions in) __tty_buffer_request_room(), so that the code returns from the fast paths immediately instead of postponing to the heavy end of the function. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: initialize variables in initializers already

2023-08-22T12:58:16+00:00

It makes the code both more compact, and more understandable. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-10-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: better types in __tty_buffer_request_room()

2023-08-22T12:58:15+00:00

* use bool for 'change' as it holds a result of a boolean. * use size_t for 'left', so it is the same as 'size' which it is compared to. Both are supposed to contain an unsigned value. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-9-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: use __tty_insert_flip_string_flags() in tty_insert_flip_char()

2023-08-22T12:58:15+00:00

Use __tty_insert_flip_string_flags() for the slow path of tty_insert_flip_char(). The former is generic enough, so there is no reason to reimplement the injection once again. So now we have a single function stuffing into tty buffers. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: let tty_prepare_flip_string() return size_t

2023-08-22T12:58:15+00:00

The same as in the previous patch, tty_prepare_flip_string() accepts size_t as an size argument. It returns the same size (or less). It is unexpected that it returns a signed value and can confuse users to check for negative values. Instead, return the same size_t as accepted to make clear we return values >= 0, where zero in fact means failure. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-7-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: switch insert functions to size_t

2023-08-22T12:58:15+00:00

All the functions accept size_t as a size argument. They finally return the same size (or less). It is quite unexpected that they return a signed value and can confuse users to check for negative values. Instead, return the same size_t as accepted to make clear we return values >= 0, where zero in fact means failure. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-6-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: warn if losing flags in __tty_insert_flip_string_flags()

2023-08-22T12:58:15+00:00

And add a WARN_ON_ONCE(need_flags) to make sure we are not losing flags in __tty_insert_flip_string_flags(). Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-5-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: unify tty_insert_flip_string_{fixed_flag,flags}()

2023-08-22T12:58:15+00:00

They both do the same except for flags. One mem-copies the flags from the caller, the other mem-sets to one flag given by the caller. This can be unified with a simple if in the unified function. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: tty_buffer: use struct_size() in tty_buffer_alloc()

2023-08-22T12:58:15+00:00

Now, that tty_buffer::data has the right type, use struct_size() for size calculation. struct_size() makes the code less error-prone and more readable. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230816105530.3335-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: use u8 for flags

2023-08-11T19:12:45+00:00

This makes all those 'char's an explicit 'u8'. This is part of the continuing unification of chars and flags to be consistent u8. This approaches tty_port_default_receive_buf(). Note that we do not change signedness as we compile with -funsigned-char. Signed-off-by: "Jiri Slaby (SUSE)" Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Max Staudt Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Dario Binacchi Cc: Andreas Koensgen Cc: Jeremy Kerr Cc: Matt Johnston Cc: Krzysztof Kozlowski Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Acked-by: Mark Brown Link: https://lore.kernel.org/r/20230810091510.13006-18-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman