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aes3k: Fix cancellation logic of aes3k driver

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The change_state function is called synchronously from the
image_captured callback. This means that deactivation of the device
happens during the img_cb function, causing the USB transfer to be
re-registered even though the device is already deactivating.

There are various ways to fix this, but it makes sense to directly bind
the cancellation to the deactivation. So create a cancellable that we
cancel at deactivation time, and make sure we always deactivate by going
through cancellation.

closes: #306
This commit is contained in:
Benjamin Berg 2020-09-07 12:13:39 +02:00 committed by Benjamin Berg
parent 3962372f47
commit bcce8876e2
1 changed files with 14 additions and 18 deletions
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30
libfprint/drivers/aes3k.c
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@ -42,8 +42,7 @@
typedef struct
{
FpiUsbTransfer *img_trf;
gboolean deactivating;
GCancellable *img_trf_cancel;
} FpiDeviceAes3kPrivate;
#define CTRL_TIMEOUT 1000
@ -77,24 +76,20 @@ img_cb (FpiUsbTransfer *transfer, FpDevice *device,
{
FpImageDevice *dev = FP_IMAGE_DEVICE (device);
FpiDeviceAes3k *self = FPI_DEVICE_AES3K (device);
FpiDeviceAes3kPrivate *priv = fpi_device_aes3k_get_instance_private (self);
FpiDeviceAes3kClass *cls = FPI_DEVICE_AES3K_GET_CLASS (self);
unsigned char *ptr = transfer->buffer;
FpImage *tmp;
FpImage *img;
int i;
priv->img_trf = NULL;
if (error)
{
if (g_error_matches (error,
G_IO_ERROR,
G_IO_ERROR_CANCELLED))
{
/* Deactivation was completed. */
/* Cancellation implies we are deactivating. */
g_error_free (error);
if (priv->deactivating)
fpi_image_device_deactivate_complete (dev, NULL);
return;
}
@ -126,21 +121,23 @@ img_cb (FpiUsbTransfer *transfer, FpDevice *device,
* it really has, then restart the capture */
fpi_image_device_report_finger_status (dev, FALSE);
/* Note: We always restart the transfer, it may already be cancelled though. */
do_capture (dev);
}
static void
do_capture (FpImageDevice *dev)
{
g_autoptr(FpiUsbTransfer) img_trf = NULL;
FpiDeviceAes3k *self = FPI_DEVICE_AES3K (dev);
FpiDeviceAes3kPrivate *priv = fpi_device_aes3k_get_instance_private (self);
FpiDeviceAes3kClass *cls = FPI_DEVICE_AES3K_GET_CLASS (self);
priv->img_trf = fpi_usb_transfer_new (FP_DEVICE (dev));
fpi_usb_transfer_fill_bulk (priv->img_trf, EP_IN, cls->data_buflen);
priv->img_trf->short_is_error = TRUE;
fpi_usb_transfer_submit (priv->img_trf, 0,
fpi_device_get_cancellable (FP_DEVICE (dev)),
img_trf = fpi_usb_transfer_new (FP_DEVICE (dev));
fpi_usb_transfer_fill_bulk (img_trf, EP_IN, cls->data_buflen);
img_trf->short_is_error = TRUE;
fpi_usb_transfer_submit (g_steal_pointer (&img_trf), 0,
priv->img_trf_cancel,
img_cb, NULL);
}
@ -159,7 +156,8 @@ aes3k_dev_activate (FpImageDevice *dev)
FpiDeviceAes3kPrivate *priv = fpi_device_aes3k_get_instance_private (self);
FpiDeviceAes3kClass *cls = FPI_DEVICE_AES3K_GET_CLASS (self);
priv->deactivating = FALSE;
g_assert (!priv->img_trf_cancel);
priv->img_trf_cancel = g_cancellable_new ();
aes_write_regv (dev, cls->init_reqs, cls->init_reqs_len, init_reqs_cb, NULL);
}
@ -169,10 +167,8 @@ aes3k_dev_deactivate (FpImageDevice *dev)
FpiDeviceAes3k *self = FPI_DEVICE_AES3K (dev);
FpiDeviceAes3kPrivate *priv = fpi_device_aes3k_get_instance_private (self);
priv->deactivating = TRUE;
if (priv->img_trf)
return;
fpi_image_device_deactivate_complete (dev, NULL);
/* Deactivation always finishes from the cancellation handler */
g_cancellable_cancel (priv->img_trf_cancel);
}
static void