[ALSA] usb-audio: add error message about missing split iso support

Modules: USB generic driver

Add an error message for -ENOSYS for situations when split iso support
is needed but not enabled.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 45157d3cf789..6fad2c40c77c 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -788,6 +788,10 @@ static const char *usb_error_string(int err)
                 return "device disabled";
         case -EHOSTUNREACH:
                 return "device suspended";
+#ifndef CONFIG_USB_EHCI_SPLIT_ISO
+        case -ENOSYS:
+                return "enable CONFIG_USB_EHCI_SPLIT_ISO to play through a hub";
+#endif
         case -EINVAL:
         case -EAGAIN:
         case -EFBIG: