There's an issue with reinitializing DLN2 hardware if ADC channel event
configurations aren't reset before suspending the driver. A physical reconnect
of the device solves the problem, but restarting the machine without a power
cycle leaves the device state inconsistent.
This patch transmits a restart command in the event of a failed init.
To the kernel's perspective, this is the rough equivalent of a disconnect and
reconnect, so another probe occurs shortly afterwards.
Signed-off-by: Jack Andersen <jackoalan@xxxxxxxxx>
---
drivers/mfd/dln2.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/mfd/dln2.c b/drivers/mfd/dln2.c
index a22ab8c..1eb0056 100644
--- a/drivers/mfd/dln2.c
+++ b/drivers/mfd/dln2.c
@@ -40,6 +40,7 @@ struct dln2_response {
#define DLN2_GENERIC_CMD(cmd) DLN2_CMD(cmd, DLN2_GENERIC_MODULE_ID)
#define CMD_GET_DEVICE_VER DLN2_GENERIC_CMD(0x30)
#define CMD_GET_DEVICE_SN DLN2_GENERIC_CMD(0x31)
+#define CMD_RESTART DLN2_GENERIC_CMD(0x43)
#define DLN2_HW_ID 0x200
#define DLN2_USB_TIMEOUT 200 /* in ms */
@@ -531,6 +532,12 @@ int dln2_transfer(struct platform_device *pdev, u16 cmd,
}
EXPORT_SYMBOL(dln2_transfer);
+static int dln2_restart(struct dln2_dev *dln2)
+{
+ return _dln2_transfer(dln2, DLN2_HANDLE_CTRL, CMD_RESTART,
+ NULL, 0, NULL, NULL);
+}
+
static int dln2_check_hw(struct dln2_dev *dln2)
{
int ret;
@@ -782,7 +789,9 @@ static int dln2_probe(struct usb_interface *interface,
ret = dln2_hw_init(dln2);
if (ret < 0) {
- dev_err(dev, "failed to initialize hardware\n");
+ dev_err(dev,
+ "failed to initialize hardware; attempting restart\n");
+ dln2_restart(dln2);
goto out_stop_rx;
}
--
1.9.1
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