commit0090114d33upstream. The CPPI 4.1 driver polls register to workaround the premature TX interrupt issue, but it causes audio playback underrun when triggered in Isoch transfers. Isoch doesn't do back-to-back transfers, the TX should be done by the time the next transfer is scheduled. So skip this polling workaround for Isoch transfer. Fixes:a655f481d8("usb: musb: musb_cppi41: handle pre-mature TX complete interrupt") Reported-by: Alexandre Bailon <abailon@baylibre.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Alexandre Bailon <abailon@baylibre.com> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>