From: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
To: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Jiri Slaby <jslaby@suse.com>,
Andrzej Pietrasiewicz <andrzej.p@collabora.com>,
kernel@collabora.com
Subject: [PATCH] tty/sysrq: Add alternative SysRq key
Date: Fri, 19 Jun 2020 18:28:19 +0200 [thread overview]
Message-ID: <20200619162819.715-1-andrzej.p@collabora.com> (raw)
In-Reply-To: <20200511180145.GU89269@dtor-ws>
There exist machines which don't have SysRq key at all, e.g. chromebooks.
This patch allows configuring an alternative key to act as SysRq. Devices
which declare KEY_SYSRQ in their 'keybit' bitmap continue using KEY_SYSRQ,
but other devices use the alternative SysRq key instead, by default F10.
Which key is actually used can be modified with sysrq's module parameter.
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
---
drivers/tty/sysrq.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 0dc3878794fd..e1d271c84746 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -604,6 +604,7 @@ EXPORT_SYMBOL(handle_sysrq);
#ifdef CONFIG_INPUT
static int sysrq_reset_downtime_ms;
+static unsigned short alternative_sysrq_key = KEY_F10;
/* Simple translation table for the SysRq keys */
static const unsigned char sysrq_xlate[KEY_CNT] =
@@ -621,6 +622,7 @@ struct sysrq_state {
unsigned long key_down[BITS_TO_LONGS(KEY_CNT)];
unsigned int alt;
unsigned int alt_use;
+ unsigned short sysrq_key;
bool active;
bool need_reinject;
bool reinjecting;
@@ -770,10 +772,10 @@ static void sysrq_reinject_alt_sysrq(struct work_struct *work)
/* Simulate press and release of Alt + SysRq */
input_inject_event(handle, EV_KEY, alt_code, 1);
- input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1);
+ input_inject_event(handle, EV_KEY, sysrq->sysrq_key, 1);
input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
- input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0);
+ input_inject_event(handle, EV_KEY, sysrq->sysrq_key, 0);
input_inject_event(handle, EV_KEY, alt_code, 0);
input_inject_event(handle, EV_SYN, SYN_REPORT, 1);
@@ -805,6 +807,7 @@ static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
}
break;
+key_sysrq:
case KEY_SYSRQ:
if (value == 1 && sysrq->alt != KEY_RESERVED) {
sysrq->active = true;
@@ -825,11 +828,15 @@ static bool sysrq_handle_keypress(struct sysrq_state *sysrq,
* triggering print screen function.
*/
if (sysrq->active)
- clear_bit(KEY_SYSRQ, sysrq->handle.dev->key);
+ clear_bit(sysrq->sysrq_key, sysrq->handle.dev->key);
break;
default:
+ /* handle non-default sysrq key */
+ if (code == sysrq->sysrq_key)
+ goto key_sysrq;
+
if (sysrq->active && value && value != 2) {
sysrq->need_reinject = false;
__handle_sysrq(sysrq_xlate[code], true);
@@ -924,6 +931,14 @@ static int sysrq_connect(struct input_handler *handler,
sysrq->handle.private = sysrq;
timer_setup(&sysrq->keyreset_timer, sysrq_do_reset, 0);
+ if (test_bit(KEY_SYSRQ, dev->keybit)) {
+ sysrq->sysrq_key = KEY_SYSRQ;
+ pr_info("%s: using default sysrq key [%x]\n", dev->name, KEY_SYSRQ);
+ } else {
+ sysrq->sysrq_key = alternative_sysrq_key;
+ pr_info("%s: Using alternative sysrq key: [%x]\n", dev->name, sysrq->sysrq_key);
+ }
+
error = input_register_handle(&sysrq->handle);
if (error) {
pr_err("Failed to register input sysrq handler, error %d\n",
@@ -1032,6 +1047,13 @@ module_param_array_named(reset_seq, sysrq_reset_seq, sysrq_reset_seq,
module_param_named(sysrq_downtime_ms, sysrq_reset_downtime_ms, int, 0644);
+module_param(alternative_sysrq_key, ushort, 0644);
+MODULE_PARM_DESC(alternative_sysrq_key,
+ "Alternative SysRq key for input devices that don't have SysRq key. F10 by default.\n"
+ "Example\n"
+ "Using F9 as SysRq:\n"
+ "sysrq.alternative_sysrq_key=0x43\n");
+
#else
static inline void sysrq_register_handler(void)
base-commit: 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162
--
2.17.1
next parent reply other threads:[~2020-06-19 16:28 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200511180145.GU89269@dtor-ws>
2020-06-19 16:28 ` Andrzej Pietrasiewicz [this message]
2020-06-21 21:21 ` [PATCH] tty/sysrq: Add alternative SysRq key Pavel Machek
2020-06-26 11:07 ` Andrzej Pietrasiewicz
2020-06-22 6:24 ` Jiri Slaby
2020-06-26 11:51 ` Andrzej Pietrasiewicz
2020-07-09 5:05 ` Dmitry Torokhov
2020-07-09 8:15 ` Andrzej Pietrasiewicz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200619162819.715-1-andrzej.p@collabora.com \
--to=andrzej.p@collabora.com \
--cc=dmitry.torokhov@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.com \
--cc=kernel@collabora.com \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).