diff options
| author | Jussi Kivilinna <jussi.kivilinna@haltian.com> | 2016-08-12 17:29:34 +0300 |
|---|---|---|
| committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2016-08-25 12:13:10 +0300 |
| commit | 1de2ebfb8cd522ad7d0deae94ae47592f975e017 (patch) | |
| tree | 538e1a7fb27d94f8a6e05e5b0047bbc9e650094a /drivers/usb/gadget/udc/net2280.c | |
| parent | 1650113888fe7b7e16604a5019c32dd3ddeb3af2 (diff) | |
usb: gadget: net2280: fix infinite loop in irq handler
With SuperSpeed CDC NCM gadget, net2280 would get stuck in
'handle_ep_small' function. Triggering issue requires large
TCP transfer from host to USB3380.
Patch adds check for stuck condition and prevents hard lockup.
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@haltian.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/gadget/udc/net2280.c')
| -rw-r--r-- | drivers/usb/gadget/udc/net2280.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c index 614ab951a4ae..cd876bff5106 100644 --- a/drivers/usb/gadget/udc/net2280.c +++ b/drivers/usb/gadget/udc/net2280.c @@ -1137,8 +1137,10 @@ dma_done(struct net2280_ep *ep, struct net2280_request *req, u32 dmacount, done(ep, req, status); } -static void scan_dma_completions(struct net2280_ep *ep) +static int scan_dma_completions(struct net2280_ep *ep) { + int num_completed = 0; + /* only look at descriptors that were "naturally" retired, * so fifo and list head state won't matter */ @@ -1166,6 +1168,7 @@ static void scan_dma_completions(struct net2280_ep *ep) break; /* single transfer mode */ dma_done(ep, req, tmp, 0); + num_completed++; break; } else if (!ep->is_in && (req->req.length % ep->ep.maxpacket) && @@ -1194,7 +1197,10 @@ static void scan_dma_completions(struct net2280_ep *ep) } } dma_done(ep, req, tmp, 0); + num_completed++; } + + return num_completed; } static void restart_dma(struct net2280_ep *ep) @@ -2547,8 +2553,11 @@ static void handle_ep_small(struct net2280_ep *ep) /* manual DMA queue advance after short OUT */ if (likely(ep->dma)) { if (t & BIT(SHORT_PACKET_TRANSFERRED_INTERRUPT)) { - u32 count; + struct net2280_request *stuck_req = NULL; int stopped = ep->stopped; + int num_completed; + int stuck = 0; + u32 count; /* TRANSFERRED works around OUT_DONE erratum 0112. * we expect (N <= maxpacket) bytes; host wrote M. @@ -2560,7 +2569,7 @@ static void handle_ep_small(struct net2280_ep *ep) /* any preceding dma transfers must finish. * dma handles (M >= N), may empty the queue */ - scan_dma_completions(ep); + num_completed = scan_dma_completions(ep); if (unlikely(list_empty(&ep->queue) || ep->out_overflow)) { req = NULL; @@ -2580,6 +2589,31 @@ static void handle_ep_small(struct net2280_ep *ep) req = NULL; break; } + + /* Escape loop if no dma transfers completed + * after few retries. + */ + if (num_completed == 0) { + if (stuck_req == req && + readl(&ep->dma->dmadesc) != + req->td_dma && stuck++ > 5) { + count = readl( + &ep->dma->dmacount); + count &= DMA_BYTE_COUNT_MASK; + req = NULL; + ep_dbg(ep->dev, "%s escape stuck %d, count %u\n", + ep->ep.name, stuck, + count); + break; + } else if (stuck_req != req) { + stuck_req = req; + stuck = 0; + } + } else { + stuck_req = NULL; + stuck = 0; + } + udelay(1); } |