Currently GEVNTCOUNT is written in the threaded interrupt handler while
processing each event. This commit moves the GEVNTCOUNT write to the
hard IRQ. We then copy the events to a separate buffer for the event
handler to read from.
This change is in preparation of working around an issue in core version
3.00a where the interrupt cannot be de-asserted in the normal way.
However, if we enable interrupt moderation, we can also de-assert it by
writing to GEVNTCOUNT.
Signed-off-by: John Youn <johnyoun@xxxxxxxxxxxx>
---
drivers/usb/dwc3/core.c | 4 ++++
drivers/usb/dwc3/core.h | 2 ++
drivers/usb/dwc3/gadget.c | 7 ++++---
3 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index d024d47..87d0cfb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -224,6 +224,10 @@ static struct dwc3_event_buffer *dwc3_alloc_one_event_buffer(struct dwc3 *dwc,
evt->dwc = dwc;
evt->length = length;
+ evt->cache = devm_kzalloc(dwc->dev, length, GFP_KERNEL);
+ if (!evt->cache)
+ return ERR_PTR(-ENOMEM);
+
evt->buf = dma_alloc_coherent(dwc->dev, length,
&evt->dma, GFP_KERNEL);
if (!evt->buf)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 354de24..bf63756 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -472,6 +472,7 @@ struct dwc3_trb;
/**
* struct dwc3_event_buffer - Software event buffer representation
* @buf: _THE_ buffer
+ * @cache: The buffer cache used in the threaded interrupt
* @length: size of this buffer
* @lpos: event offset
* @count: cache of last read event count register
@@ -481,6 +482,7 @@ struct dwc3_trb;
*/
struct dwc3_event_buffer {
void *buf;
+ void *cache;
unsigned length;
unsigned int lpos;
unsigned int count;
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 230ffa3..baa2c64 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2821,7 +2821,7 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
while (left > 0) {
union dwc3_event event;
- event.raw = *(u32 *) (evt->buf + evt->lpos);
+ event.raw = *(u32 *)(evt->cache + evt->lpos);
dwc3_process_event_entry(dwc, &event);
@@ -2836,8 +2836,6 @@ static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
*/
evt->lpos = (evt->lpos + 4) % DWC3_EVENT_BUFFERS_SIZE;
left -= 4;
-
- dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 4);
}
evt->count = 0;
@@ -2892,6 +2890,9 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
reg |= DWC3_GEVNTSIZ_INTMASK;
dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);
+ memcpy(evt->cache, evt->buf, DWC3_EVENT_BUFFERS_SIZE);
+ dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count);
+
return IRQ_WAKE_THREAD;
}
--
2.10.0
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