adbd: Don't close/reopen FFS ep0 on disconnect
In case of bulk read/write failure or disconnect, transport_usb
calls usb_ffs_kick in order to force the daemon to re-open the
FunctionFS ep files as a way to soft restart the kernel driver.
However, there's no reason to always close the ep0 file, as it
would need to be reopened and the descriptors rewritten--this
is unnecessary, especially in the simple/frequent case of cable
disconnect, and causes the kernel driver to unbind and bind *all*
of the function drivers. This is causing USB Chapter 9 tests to fail.
Thus, try to reuse the same ep0 file handle across reconnects. In
case there is a failure, the ep1/ep2 opens would fail and all the
file handles get dropped. For the adb root case, the entire daemon
gets restarted anyway.
Change-Id: I0840085c52a0795dcb2d751c39aa4a436c039ee2
diff --git a/usb_linux_client.c b/usb_linux_client.c
index fb1dad0..f20772b 100644
--- a/usb_linux_client.c
+++ b/usb_linux_client.c
@@ -264,23 +264,25 @@
{
ssize_t ret;
- D("OPENING %s\n", USB_FFS_ADB_EP0);
- h->control = adb_open(USB_FFS_ADB_EP0, O_RDWR);
- if (h->control < 0) {
- D("[ %s: cannot open control endpoint: errno=%d]\n", USB_FFS_ADB_EP0, errno);
- goto err;
- }
+ if (h->control < 0) { // might have already done this before
+ D("OPENING %s\n", USB_FFS_ADB_EP0);
+ h->control = adb_open(USB_FFS_ADB_EP0, O_RDWR);
+ if (h->control < 0) {
+ D("[ %s: cannot open control endpoint: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+ goto err;
+ }
- ret = adb_write(h->control, &descriptors, sizeof(descriptors));
- if (ret < 0) {
- D("[ %s: write descriptors failed: errno=%d ]\n", USB_FFS_ADB_EP0, errno);
- goto err;
- }
+ ret = adb_write(h->control, &descriptors, sizeof(descriptors));
+ if (ret < 0) {
+ D("[ %s: write descriptors failed: errno=%d ]\n", USB_FFS_ADB_EP0, errno);
+ goto err;
+ }
- ret = adb_write(h->control, &strings, sizeof(strings));
- if (ret < 0) {
- D("[ %s: writing strings failed: errno=%d]\n", USB_FFS_ADB_EP0, errno);
- goto err;
+ ret = adb_write(h->control, &strings, sizeof(strings));
+ if (ret < 0) {
+ D("[ %s: writing strings failed: errno=%d]\n", USB_FFS_ADB_EP0, errno);
+ goto err;
+ }
}
h->bulk_out = adb_open(USB_FFS_ADB_OUT, O_RDWR);
@@ -320,14 +322,14 @@
while (1) {
// wait until the USB device needs opening
adb_mutex_lock(&usb->lock);
- while (usb->control != -1)
+ while (usb->control != -1 && usb->bulk_in != -1 && usb->bulk_out != -1)
adb_cond_wait(&usb->notify, &usb->lock);
adb_mutex_unlock(&usb->lock);
while (1) {
init_functionfs(usb);
- if (usb->control >= 0)
+ if (usb->control >= 0 && usb->bulk_in >= 0 && usb->bulk_out >= 0)
break;
adb_sleep_ms(1000);
@@ -424,10 +426,13 @@
D("[ kick: sink (fd=%d) clear halt failed (%d) ]", h->bulk_out, errno);
adb_mutex_lock(&h->lock);
- adb_close(h->control);
+
+ // don't close ep0 here, since we may not need to reinitialize it with
+ // the same descriptors again. if however ep1/ep2 fail to re-open in
+ // init_functionfs, only then would we close and open ep0 again.
adb_close(h->bulk_out);
adb_close(h->bulk_in);
- h->control = h->bulk_out = h->bulk_in = -1;
+ h->bulk_out = h->bulk_in = -1;
// notify usb_ffs_open_thread that we are disconnected
adb_cond_signal(&h->notify);