usb: dfu: f_dfu: Provide infrastructure to adjust DFU's Poll Timeout value

It is necessary to deter the host from sending subsequent DFU_GETSTATUS
request in the case of e.g. writing the buffer to medium.

Here the timeout is increased when we fill up the whole buffer. This delay
allows eMMC memory to perform its internal operations.
Otherwise we end up with HOST's error regarding GET_STATUS receive timeout.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>

2 files changed, 38 insertions, 3 deletions

diff --git a/drivers/usb/gadget/f_dfu.c b/drivers/usb/gadget/f_dfu.c
index 37d04a1..b4b4aa4 100644
--- a/drivers/usb/gadget/f_dfu.c
+++ b/drivers/usb/gadget/f_dfu.c
@@ -40,6 +40,7 @@ struct f_dfu {
 
 	/* Send/received block number is handy for data integrity check */
 	int                             blk_seq_num;
+	unsigned int                    poll_timeout;
 };
 
 typedef int (*dfu_state_fn) (struct f_dfu *,
@@ -128,6 +129,33 @@ static struct usb_gadget_strings *dfu_strings[] = {
 	NULL,
 };
 
+static void dfu_set_poll_timeout(struct dfu_status *dstat, unsigned int ms)
+{
+	/*
+	 * The bwPollTimeout DFU_GETSTATUS request payload provides information
+	 * about minimum time, in milliseconds, that the host should wait before
+	 * sending a subsequent DFU_GETSTATUS request
+	 *
+	 * This permits the device to vary the delay depending on its need to
+	 * erase or program the memory
+	 *
+	 */
+
+	unsigned char *p = (unsigned char *)&ms;
+
+	if (!ms || (ms & ~DFU_POLL_TIMEOUT_MASK)) {
+		dstat->bwPollTimeout[0] = 0;
+		dstat->bwPollTimeout[1] = 0;
+		dstat->bwPollTimeout[2] = 0;
+
+		return;
+	}
+
+	dstat->bwPollTimeout[0] = *p++;
+	dstat->bwPollTimeout[1] = *p++;
+	dstat->bwPollTimeout[2] = *p;
+}
+
 /*-------------------------------------------------------------------------*/
 
 static void dnload_request_complete(struct usb_ep *ep, struct usb_request *req)
@@ -157,11 +185,15 @@ static void handle_getstatus(struct usb_request *req)
 		break;
 	}
 
+	dfu_set_poll_timeout(dstat, 0);
+
+	if (f_dfu->poll_timeout)
+		if (!(f_dfu->blk_seq_num %
+		      (dfu_get_buf_size() / DFU_USB_BUFSIZ)))
+			dfu_set_poll_timeout(dstat, f_dfu->poll_timeout);
+
 	/* send status response */
 	dstat->bStatus = f_dfu->dfu_status;
-	dstat->bwPollTimeout[0] = 0;
-	dstat->bwPollTimeout[1] = 0;
-	dstat->bwPollTimeout[2] = 0;
 	dstat->bState = f_dfu->dfu_state;
 	dstat->iString = 0;
 }
@@ -725,6 +757,7 @@ static int dfu_bind_config(struct usb_configuration *c)
 	f_dfu->usb_function.disable = dfu_disable;
 	f_dfu->usb_function.strings = dfu_generic_strings,
 	f_dfu->usb_function.setup = dfu_handle,
+	f_dfu->poll_timeout = DFU_DEFAULT_POLL_TIMEOUT;
 
 	status = usb_add_function(c, &f_dfu->usb_function);
 	if (status)
diff --git a/drivers/usb/gadget/f_dfu.h b/drivers/usb/gadget/f_dfu.h
index cc2c455..0c29954 100644
--- a/drivers/usb/gadget/f_dfu.h
+++ b/drivers/usb/gadget/f_dfu.h
@@ -82,4 +82,6 @@ struct dfu_function_descriptor {
 	__le16				wTransferSize;
 	__le16				bcdDFUVersion;
 } __packed;
+
+#define DFU_POLL_TIMEOUT_MASK           (0xFFFFFFUL)
 #endif /* __F_DFU_H_ */