[PATCH v1 11/19] hw/usb/aspeed-udc: Clear EP_POOL_ACK when no endpoint ack is left

[Jamin Lin <jamin_lin@aspeedtech.com>]

UDC_ISR.EP_POOL_ACK says that at least one endpoint in UDC_EP_ACK_ISR
has an ack. It is read only, so a write cannot clear it.

Clear it when bits 3:0 of UDC_EP_ACK_ISR are all 0, which means no
programmable endpoint has an ack.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
---
 hw/usb/aspeed-udc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/usb/aspeed-udc.c b/hw/usb/aspeed-udc.c
index 95fe823534..bdbd1a78b8 100644
--- a/hw/usb/aspeed-udc.c
+++ b/hw/usb/aspeed-udc.c
@@ -335,6 +335,13 @@ static void aspeed_udc_write(void *opaque, hwaddr offset, uint64_t data,
         aspeed_udc_update_irq(s);
         break;
     case R_UDC_EP_ACK_ISR:
+        val &= 0x0000000f;
+        s->regs[reg] &= ~val;
+        if (!s->regs[R_UDC_EP_ACK_ISR]) {
+            s->regs[R_UDC_ISR] &= ~R_UDC_ISR_EP_POOL_ACK_MASK;
+        }
+        aspeed_udc_update_irq(s);
+        break;
     case R_UDC_EP_NAK_ISR:
         val &= 0x0000000f;
         s->regs[reg] &= ~val;
-- 
2.53.0