[snd-usb-6fire] Move DMA-buffer off of the stack

[snd-usb-6fire] Move DMA-buffer off of the stack

[René Herman]

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snd-usb-fire currently fails its firmware load with "transfer buffer not
dma capable". Move said buffer off of the stack (has been coordinated
with the original driver author Torsten Schenk)

Signed-off-by: René Herman <rene.herman@gmail.com>

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From 6a732ea2536217e1aa35c55c966df0e7873d95ca Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Herman?= <rene.herman@gmail.com>
Date: Sun, 12 Jul 2020 01:22:45 +0200
Subject: [PATCH 1/3] [snd-usb-6fire] Move DMA-buffer off the stack
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

snd-usb-fire currently fails its firmware load with "transfer buffer not dma
capable". Move said buffer off of the stack.

Signed-off-by: René Herman <rene.herman@gmail.com>
---
 sound/usb/6fire/firmware.c | 95 ++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 49 deletions(-)

diff --git a/sound/usb/6fire/firmware.c b/sound/usb/6fire/firmware.c
index 69137c14d0dc..502653a89f01 100644
--- a/sound/usb/6fire/firmware.c
+++ b/sound/usb/6fire/firmware.c
@@ -355,63 +355,60 @@ static int usb6fire_fw_check(struct usb_interface *intf, const u8 *version)
 
 int usb6fire_fw_init(struct usb_interface *intf)
 {
-	int i;
-	int ret;
 	struct usb_device *device = interface_to_usbdev(intf);
+	int ret, i;
+
 	/* buffer: 8 receiving bytes from device and
 	 * sizeof(EP_W_MAX_PACKET_SIZE) bytes for non-const copy */
-	u8 buffer[12];
+	u8 *buffer = kmalloc(12, GFP_KERNEL);
+
+	if (!buffer)
+		return -ENOMEM;
 
 	ret = usb6fire_fw_ezusb_read(device, 1, 0, buffer, 8);
 	if (ret < 0) {
 		dev_err(&intf->dev,
 			"unable to receive device firmware state.\n");
-		return ret;
-	}
-	if (buffer[0] != 0xeb || buffer[1] != 0xaa || buffer[2] != 0x55) {
-		dev_err(&intf->dev,
-			"unknown device firmware state received from device:");
-		for (i = 0; i < 8; i++)
-			printk(KERN_CONT "%02x ", buffer[i]);
-		printk(KERN_CONT "\n");
-		return -EIO;
-	}
-	/* do we need fpga loader ezusb firmware? */
-	if (buffer[3] == 0x01) {
-		ret = usb6fire_fw_ezusb_upload(intf,
-				"6fire/dmx6firel2.ihx", 0, NULL, 0);
-		if (ret < 0)
-			return ret;
-		return FW_NOT_READY;
+		goto out;
 	}
-	/* do we need fpga firmware and application ezusb firmware? */
-	else if (buffer[3] == 0x02) {
-		ret = usb6fire_fw_check(intf, buffer + 4);
-		if (ret < 0)
-			return ret;
-		ret = usb6fire_fw_fpga_upload(intf, "6fire/dmx6firecf.bin");
-		if (ret < 0)
-			return ret;
-		memcpy(buffer, ep_w_max_packet_size,
-				sizeof(ep_w_max_packet_size));
-		ret = usb6fire_fw_ezusb_upload(intf, "6fire/dmx6fireap.ihx",
-				0x0003,	buffer, sizeof(ep_w_max_packet_size));
-		if (ret < 0)
-			return ret;
-		return FW_NOT_READY;
-	}
-	/* all fw loaded? */
-	else if (buffer[3] == 0x03)
-		return usb6fire_fw_check(intf, buffer + 4);
-	/* unknown data? */
-	else {
-		dev_err(&intf->dev,
-			"unknown device firmware state received from device: ");
-		for (i = 0; i < 8; i++)
-			printk(KERN_CONT "%02x ", buffer[i]);
-		printk(KERN_CONT "\n");
-		return -EIO;
+	if (buffer[0] == 0xeb && buffer[1] == 0xaa && buffer[2] == 0x55) {
+		/* do we need fpga loader ezusb firmware? */
+		if (buffer[3] == 1) {
+			ret = usb6fire_fw_ezusb_upload(intf,
+					"6fire/dmx6firel2.ihx", 0, NULL, 0);
+			if (ret >= 0)
+				ret = FW_NOT_READY;
+			goto out;
+		}
+		/* do we need fpga firmware and application ezusb firmware? */
+		if (buffer[3] == 2) {
+			ret = usb6fire_fw_check(intf, buffer + 4);
+			if (ret < 0)
+				goto out;
+			ret = usb6fire_fw_fpga_upload(intf, "6fire/dmx6firecf.bin");
+			if (ret < 0)
+				goto out;
+			memcpy(buffer, ep_w_max_packet_size,
+					sizeof(ep_w_max_packet_size));
+			ret = usb6fire_fw_ezusb_upload(intf, "6fire/dmx6fireap.ihx",
+					0x0003,	buffer, sizeof(ep_w_max_packet_size));
+			if (ret >= 0)
+				ret = FW_NOT_READY;
+			goto out;
+		}
+		/* all fw loaded? */
+		if (buffer[3] == 3) {
+			ret = usb6fire_fw_check(intf, buffer + 4);
+			goto out;
+		}
 	}
-	return 0;
+	dev_err(&intf->dev,
+		"unknown device firmware state received from device: ");
+	for (i = 0; i < 8; i++)
+		printk(KERN_CONT "%02x ", buffer[i]);
+	printk(KERN_CONT "\n");
+	ret = -EIO;
+
+out:	kfree(buffer);
+	return ret;
 }
-
-- 
2.17.1