dmaengine: usb-dmac: check CHCR.DE bit in usb_dmac_isr_channel()

The USB-DMAC's interruption happens even if the CHCR.DE is not set to 1
because CHCR.NULLE is set to 1. So, this driver should call
usb_dmac_isr_transfer_end() if the DE bit is set to 1 only. Otherwise,
the desc is possible to be NULL in the usb_dmac_isr_transfer_end().

Fixes: 0c1c8ff32fa2 ("dmaengine: usb-dmac: Add Renesas USB DMA Controller (USB-DMAC) driver)
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index 749f1bd5d65d77c2c9f200b437ecd6d98e445361..06ecdc38cee0a32dfa312a6ada4d807a560aa47d 100644 (file)
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -600,27 +600,30 @@ static irqreturn_t usb_dmac_isr_channel(int irq, void *dev)
 {
        struct usb_dmac_chan *chan = dev;
        irqreturn_t ret = IRQ_NONE;
-       u32 mask = USB_DMACHCR_TE;
-       u32 check_bits = USB_DMACHCR_TE | USB_DMACHCR_SP;
+       u32 mask = 0;
        u32 chcr;
+       bool xfer_end = false;
 
        spin_lock(&chan->vc.lock);
 
        chcr = usb_dmac_chan_read(chan, USB_DMACHCR);
-       if (chcr & check_bits)
-               mask |= USB_DMACHCR_DE | check_bits;
+       if (chcr & (USB_DMACHCR_TE | USB_DMACHCR_SP)) {
+               mask |= USB_DMACHCR_DE | USB_DMACHCR_TE | USB_DMACHCR_SP;
+               if (chcr & USB_DMACHCR_DE)
+                       xfer_end = true;
+               ret |= IRQ_HANDLED;
+       }
        if (chcr & USB_DMACHCR_NULL) {
                /* An interruption of TE will happen after we set FTE */
                mask |= USB_DMACHCR_NULL;
                chcr |= USB_DMACHCR_FTE;
                ret |= IRQ_HANDLED;
        }
-       usb_dmac_chan_write(chan, USB_DMACHCR, chcr & ~mask);
+       if (mask)
+               usb_dmac_chan_write(chan, USB_DMACHCR, chcr & ~mask);
 
-       if (chcr & check_bits) {
+       if (xfer_end)
                usb_dmac_isr_transfer_end(chan);
-               ret |= IRQ_HANDLED;
-       }
 
        spin_unlock(&chan->vc.lock);