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[PATCH v2 6/8] dev-serial: add always-plugged property to ensure USB dev
From: |
Mark Cave-Ayland |
Subject: |
[PATCH v2 6/8] dev-serial: add always-plugged property to ensure USB device is always attached |
Date: |
Tue, 27 Oct 2020 15:04:54 +0000 |
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>
---
hw/usb/dev-serial.c | 9 ++++++---
1 file 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(),
};
--
2.20.1
- [PATCH v2 0/8] dev-serial: minor fixes and improvements, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 1/8] dev-serial: style changes to improve readability and checkpatch fixes, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 2/8] dev-serial: use USB_SERIAL QOM macro for USBSerialState assignments, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 3/8] dev-serial: convert from DPRINTF to trace-events, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 5/8] dev-serial: replace DeviceOutVendor/DeviceInVendor with equivalent macros from usb.h, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 4/8] dev-serial: add trace-events for baud rate and data parameters, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 6/8] dev-serial: add always-plugged property to ensure USB device is always attached,
Mark Cave-Ayland <=
- [PATCH v2 7/8] dev-serial: add support for setting data_bits in QEMUSerialSetParams, Mark Cave-Ayland, 2020/10/27
- [PATCH v2 8/8] dev-serial: store flow control and xon/xoff characters, Mark Cave-Ayland, 2020/10/27