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    Subject[Suspend2][ 11/21] [Suspend2] Wait for keypress.
    Date
    Wait for a keypress. This might be via userspace (normal case), or in the
    special case of an emergency message early in the process, via reading
    /dev/console. In these later cases, we can't rely on the userspace process
    existing, and want to give the user some control over what happens. We do
    implement a timeout though, so unattended boots don't hang indefinitely.

    Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

    kernel/power/ui.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
    1 files changed, 71 insertions(+), 0 deletions(-)

    diff --git a/kernel/power/ui.c b/kernel/power/ui.c
    index 3378766..6271a24 100644
    --- a/kernel/power/ui.c
    +++ b/kernel/power/ui.c
    @@ -331,3 +331,74 @@ void __suspend_message(unsigned long sec
    &msg, sizeof(msg));
    }

    +static void wait_for_key_via_userui(void)
    +{
    + DECLARE_WAITQUEUE(wait, current);
    +
    + add_wait_queue(&userui_wait_for_key, &wait);
    + set_current_state(TASK_INTERRUPTIBLE);
    +
    + interruptible_sleep_on(&userui_wait_for_key);
    +
    + set_current_state(TASK_RUNNING);
    + remove_wait_queue(&userui_wait_for_key, &wait);
    +}
    +
    +char suspend_wait_for_keypress(int timeout)
    +{
    + int fd;
    + char key = '\0';
    + struct termios t, t_backup;
    +
    + if (ui_helper_data.pid != -1) {
    + wait_for_key_via_userui();
    + key = ' ';
    + goto out;
    + }
    +
    + /* We should be guaranteed /dev/console exists after populate_rootfs() in
    + * init/main.c
    + */
    + if ((fd = sys_open("/dev/console", O_RDONLY, 0)) < 0) {
    + printk("Couldn't open /dev/console.\n");
    + goto out;
    + }
    +
    + if (sys_ioctl(fd, TCGETS, (long)&t) < 0)
    + goto out_close;
    +
    + memcpy(&t_backup, &t, sizeof(t));
    +
    + t.c_lflag &= ~(ISIG|ICANON|ECHO);
    + t.c_cc[VMIN] = 0;
    + if (timeout)
    + t.c_cc[VTIME] = timeout*10;
    +
    + if (sys_ioctl(fd, TCSETS, (long)&t) < 0)
    + goto out_restore;
    +
    + while (1) {
    + if (sys_read(fd, &key, 1) <= 0) {
    + key = '\0';
    + break;
    + }
    + key = tolower(key);
    + if (test_suspend_state(SUSPEND_SANITY_CHECK_PROMPT)) {
    + if (key == 'c') {
    + set_suspend_state(SUSPEND_CONTINUE_REQ);
    + break;
    + } else if (key == ' ')
    + break;
    + } else
    + break;
    + }
    +
    +out_restore:
    + sys_ioctl(fd, TCSETS, (long)&t_backup);
    +
    +out_close:
    + sys_close(fd);
    +out:
    + return key;
    +}
    +
    --
    Nigel Cunningham nigel at suspend2 dot net
    -
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