From: Paul Cercueil <[email protected]>

commit 685f5f24108a5f3481da70ee75a1b18b9de34257 upstream.

The function dma_controller_irq() locks up the exact same spinlock we
locked before calling it, which obviously resulted in a deadlock when
CONFIG_SMP was enabled. This flew under the radar as none of the boards
supported by this driver needs SMP.

Fixes: 57aadb46bd63 ("usb: musb: jz4740: Add support for DMA")

Cc: [email protected]
Signed-off-by: Paul Cercueil <[email protected]>
Signed-off-by: Bin Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 drivers/usb/musb/jz4740.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/musb/jz4740.c
+++ b/drivers/usb/musb/jz4740.c
@@ -30,11 +30,11 @@ static irqreturn_t jz4740_musb_interrupt
        irqreturn_t     retval = IRQ_NONE, retval_dma = IRQ_NONE;
        struct musb     *musb = __hci;
 
-       spin_lock_irqsave(&musb->lock, flags);
-
        if (IS_ENABLED(CONFIG_USB_INVENTRA_DMA) && musb->dma_controller)
                retval_dma = dma_controller_irq(irq, musb->dma_controller);
 
+       spin_lock_irqsave(&musb->lock, flags);
+
        musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
        musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
        musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);


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