From e879dae59e057343a15091f55c54a354623d8142 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Thu, 4 Aug 2016 19:59:41 +0900 Subject: [PATCH] dmaengine: usb-dmac: check CHCR.DE bit in usb_dmac_isr_channel() commit 626d2f07de89bf6be3d7301524d0ab3375b81b9c upstream. 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) Signed-off-by: Yoshihiro Shimoda Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/sh/usb-dmac.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c index f1bcc2a163b3..b1bc945f008f 100644 --- 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); -- 2.20.1