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

tty: make tty_operations::write()'s count size_t

2023-08-11T19:12:46+00:00

Unify with the rest of the code. Use size_t for counts and ssize_t for retval. Signed-off-by: "Jiri Slaby (SUSE)" Link: https://lore.kernel.org/r/20230810091510.13006-30-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Fix race condition releasing tty port

2022-01-26T13:50:26+00:00

The tty_port struct is part of the rpmsg_tty_port structure. The issue is that the rpmsg_tty_port structure is freed on rpmsg_tty_remove while it is still referenced in the tty_struct. Its release is not predictable due to workqueues. For instance following ftrace shows that rpmsg_tty_close is called after rpmsg_tty_release_cport: nr_test.sh-389 [000] ..... 212.093752: rpmsg_tty_remove <-rpmsg_dev_ remove cat-1191 [001] ..... 212.095697: tty_release <-__fput nr_test.sh-389 [000] ..... 212.099166: rpmsg_tty_release_cport <-rpm sg_tty_remove cat-1191 [001] ..... 212.115352: rpmsg_tty_close <-tty_release cat-1191 [001] ..... 212.115371: release_tty <-tty_release_str As consequence, the port must be free only when user has released the TTY interface. This path : - Introduce the .destruct port tty ops function to release the allocated rpmsg_tty_port structure. - Introduce the .hangup tty ops function to call tty_port_hangup. - Manages the tty port refcounting to trig the .destruct port ops, - Introduces the rpmsg_tty_cleanup function to ensure that the TTY is removed before decreasing the port refcount. Fixes: 7c0408d80579 ("tty: add rpmsg driver") Cc: stable Signed-off-by: Arnaud Pouliquen Link: https://lore.kernel.org/r/20220104163545.34710-1-arnaud.pouliquen@foss.st.com Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Define tty name via constant string literal

2021-10-26T17:19:42+00:00

Driver uses already twice the same string literal. Define it in one place, so every user will have this name consistent. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211025135148.53944-5-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Add pr_fmt() to prefix messages

2021-10-26T17:19:41+00:00

Make all messages to be prefixed in a unified way. Add pr_fmt() to achieve this. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211025135148.53944-4-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Use dev_err_probe() in ->probe()

2021-10-26T17:19:41+00:00

It's fine to use dev_err_probe() in ->probe() even if we know it won't be deferred. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211025135148.53944-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Unify variable used to keep an error code

2021-10-26T17:19:41+00:00

In some ret is used, in the other err. Let's unify it across the driver. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211025135148.53944-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: rpmsg: Assign returned id to a local variable

2021-10-26T17:19:41+00:00

Instead of putting garbage in the data structure, assign allocated id or an error code to a temporary variable. This makes code cleaner. Signed-off-by: Andy Shevchenko Link: https://lore.kernel.org/r/20211025135148.53944-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: add rpmsg driver

2021-10-21T10:35:35+00:00

This driver exposes a standard TTY interface on top of the rpmsg framework through a rpmsg service. This driver supports multi-instances, offering a /dev/ttyRPMSGx entry per rpmsg endpoint. Reviewed-by: Mathieu Poirier Signed-off-by: Arnaud Pouliquen Link: https://lore.kernel.org/r/20211015094701.5732-3-arnaud.pouliquen@foss.st.com Signed-off-by: Greg Kroah-Hartman