ALSA: usb-audio: Fix undefined behavior due to shift overflowing the constant

Fix:

  sound/usb/midi.c: In function ‘snd_usbmidi_out_endpoint_create’:
  sound/usb/midi.c:1389:2: error: case label does not reduce to an integer constant
    case USB_ID(0xfc08, 0x0101): /* Unknown vendor Cable */
    ^~~~

See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@zn.tnic for the gory
details as to why it triggers with older gccs only.

[ A slight correction with parentheses around the argument by tiwai ]

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220405151517.29753-3-bp@alien8.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 167834133b9bc8b81a8333f32938fceba6eb7810..b8359a0aa008a0a9f5dfcffb232cbe46ff2094d6 100644 (file)
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -8,7 +8,7 @@
  */
 
 /* handling of USB vendor/product ID pairs as 32-bit numbers */
-#define USB_ID(vendor, product) (((vendor) << 16) | (product))
+#define USB_ID(vendor, product) (((unsigned int)(vendor) << 16) | (product))
 #define USB_ID_VENDOR(id) ((id) >> 16)
 #define USB_ID_PRODUCT(id) ((u16)(id))