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authorDaniel Starke <daniel.starke@siemens.com>2023-03-15 13:53:52 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-03-29 11:50:48 +0300
commit4ca589661d964840d0d5de4b3baabbef78f453e3 (patch)
tree51bdebd25258a7aa020524a209ec877126da0310 /Documentation
parentcb95de8d4317b9335f1e8b687bca714cd5713502 (diff)
downloadlinux-4ca589661d964840d0d5de4b3baabbef78f453e3.tar.xz
tty: n_gsm: add ioctl for DLC specific parameter configuration
Parameter negotiation has been introduced with commit 92f1f0c3290d ("tty: n_gsm: add parameter negotiation support") However, means to set individual parameters per DLCI are not yet implemented. Furthermore, it is currently not possible to keep a DLCI half open until the user application sets the right parameters for it. This is required to allow a user application to set its specific parameters before the underlying link is established. Otherwise, the link is opened and re-established right afterwards if the user application sets incompatible parameters. This may be an unexpected behavior for the peer. Add parameter 'wait_config' to 'gsm_config' to support setups where the DLCI specific user application sets its specific parameters after open() and before the link gets fully established. Setting this to zero disables the user application specific DLCI configuration option. Add the ioctls 'GSMIOC_GETCONF_DLCI' and 'GSMIOC_SETCONF_DLCI' for the ldisc and virtual ttys. This gets/sets the DLCI specific parameters and may trigger a reconnect of the DLCI if incompatible values have been set. Only the parameters for the DLCI associated with the virtual tty can be set or retrieved if called on these. Add remark within the documentation to introduce the new ioctls. Link: https://lore.kernel.org/oe-kbuild-all/202302281856.S9Lz4gHB-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20230315105354.6234-1-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/driver-api/tty/n_gsm.rst4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/driver-api/tty/n_gsm.rst b/Documentation/driver-api/tty/n_gsm.rst
index 9447b8a3b8e2..c2624546fb8f 100644
--- a/Documentation/driver-api/tty/n_gsm.rst
+++ b/Documentation/driver-api/tty/n_gsm.rst
@@ -29,6 +29,8 @@ Config Initiator
#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.
+#. Configure DLCs using ``GSMIOC_GETCONF_DLCI``/``GSMIOC_SETCONF_DLCI`` ioctl for non-defaults.
+
#. Obtain base gsmtty number for the used serial port.
Major parts of the initialization program
@@ -120,6 +122,8 @@ Config Requester
#. Configure the mux using ``GSMIOC_GETCONF``/``GSMIOC_SETCONF`` ioctl.
+#. Configure DLCs using ``GSMIOC_GETCONF_DLCI``/``GSMIOC_SETCONF_DLCI`` ioctl for non-defaults.
+
#. Obtain base gsmtty number for the used serial port::
#include <stdio.h>