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authorMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>2020-10-27 15:04:54 +0000
committerGerd Hoffmann <kraxel@redhat.com>2020-11-04 07:22:37 +0100
commit66007a95674d4b8e616245541faad6cdf5e9f70d (patch)
treec0d874f07dff9a062283fda01a203358d88d358d /hw/usb
parent687dfe63e3d9dd8a1a682a7da76bec75a5f656ba (diff)
dev-serial: add always-plugged property to ensure USB device is always attached
Some operating systems will generate a new device ID when a USB device is unplugged and then replugged into the USB. If this is done whilst switching between multiple applications over a virtual serial port, the change of device ID requires going back into the OS/application to locate the new device accordingly. Add a new always-plugged property that if specified will ensure that the device always remains attached to the USB regardless of the state of the backend chardev. Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Message-id: 20201027150456.24606-7-mark.cave-ayland@ilande.co.uk Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/usb')
-rw-r--r--hw/usb/dev-serial.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/hw/usb/dev-serial.c b/hw/usb/dev-serial.c
index 92c35615eb..b9e308dca1 100644
--- a/hw/usb/dev-serial.c
+++ b/hw/usb/dev-serial.c
@@ -97,6 +97,7 @@ struct USBSerialState {
uint8_t event_chr;
uint8_t error_chr;
uint8_t event_trigger;
+ bool always_plugged;
QEMUSerialSetParams params;
int latency; /* ms */
CharBackend cs;
@@ -516,12 +517,12 @@ static void usb_serial_event(void *opaque, QEMUChrEvent event)
s->event_trigger |= FTDI_BI;
break;
case CHR_EVENT_OPENED:
- if (!s->dev.attached) {
+ if (!s->always_plugged && !s->dev.attached) {
usb_device_attach(&s->dev, &error_abort);
}
break;
case CHR_EVENT_CLOSED:
- if (s->dev.attached) {
+ if (!s->always_plugged && s->dev.attached) {
usb_device_detach(&s->dev);
}
break;
@@ -556,7 +557,8 @@ static void usb_serial_realize(USBDevice *dev, Error **errp)
usb_serial_event, NULL, s, NULL, true);
usb_serial_handle_reset(dev);
- if (qemu_chr_fe_backend_open(&s->cs) && !dev->attached) {
+ if ((s->always_plugged || qemu_chr_fe_backend_open(&s->cs)) &&
+ !dev->attached) {
usb_device_attach(dev, &error_abort);
}
s->intr = usb_ep_get(dev, USB_TOKEN_IN, 1);
@@ -584,6 +586,7 @@ static const VMStateDescription vmstate_usb_serial = {
static Property serial_properties[] = {
DEFINE_PROP_CHR("chardev", USBSerialState, cs),
+ DEFINE_PROP_BOOL("always-plugged", USBSerialState, always_plugged, false),
DEFINE_PROP_END_OF_LIST(),
};