During dma teardown for dequque urb, musb might generate bogus rx ep
interrupt even when the rx fifo is flushed. As mentioned in the current
inline comment, clearing ep interrupt in the teardown path avoids the
bogus interrupt.
Before this change, any of the follow log messages could happen when
musb load is high.
musb_host_rx 1853: BOGUS RX2 ready, csr 0000, count 0
musb_host_rx 1936: RX3 dma busy, csr 2020
cc: stable@xxxxxxxxxxxxxxx # 4.1+
Signed-off-by: Bin Liu <b-liu@xxxxxx>
---
drivers/usb/musb/musb_core.h | 7 +++++++
drivers/usb/musb/musb_host.c | 10 ++++------
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index ed5e354b0891..deb64fe896b2 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -216,6 +216,7 @@ struct musb_platform_ops {
void (*pre_root_reset_end)(struct musb *musb);
void (*post_root_reset_end)(struct musb *musb);
int (*phy_callback)(enum musb_vbus_id_status status);
+ void (*clear_ep_rxintr)(struct musb *musb, int epnum);
};
/*
@@ -619,6 +620,12 @@ static inline void musb_platform_post_root_reset_end(struct musb *musb)
musb->ops->post_root_reset_end(musb);
}
+static inline void musb_platform_clear_ep_rxintr(struct musb *musb, int epnum)
+{
+ if (musb->ops->clear_ep_rxintr)
+ musb->ops->clear_ep_rxintr(musb, epnum);
+}
+
/*
* gets the "dr_mode" property from DT and converts it into musb_mode
* if the property is not found or not recognized returns MUSB_OTG
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 30d394b3f2f6..613009abd766 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -2374,12 +2374,11 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
int is_in = usb_pipein(urb->pipe);
int status = 0;
u16 csr;
+ struct dma_channel *dma = NULL;
musb_ep_select(regs, hw_end);
if (is_dma_capable()) {
- struct dma_channel *dma;
-
dma = is_in ? ep->rx_channel : ep->tx_channel;
if (dma) {
status = ep->musb->dma_controller->channel_abort(dma);
@@ -2395,10 +2394,9 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
/* giveback saves bulk toggle */
csr = musb_h_flush_rxfifo(ep, 0);
- /* REVISIT we still get an irq; should likely clear the
- * endpoint's irq status here to avoid bogus irqs.
- * clearing that status is platform-specific...
- */
+ /* clear the endpoint's irq status here to avoid bogus irqs */
+ if (is_dma_capable() && dma)
+ musb_platform_clear_ep_rxintr(musb, ep->epnum);
} else if (ep->epnum) {
csr = musb_readw(epio, MUSB_TXCSR);
if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
--
1.9.1
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