Messages in this thread Patch in this message | | | Date | Wed, 02 Mar 2016 14:58:40 +0200 | From | Mathias Nyman <> | Subject | Re: [PATCH v7 07/10] usb: dbc: handle endpoint stall |
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On 26.01.2016 14:58, Lu Baolu wrote: > In case of endpoint stall, software is able to detect the situation > by reading DCCTRL.HIT or DCCTRL.HOT bits. DbC follows the normal USB > framework to handle endpoint stall. When software detects endpoint > stall situation, it should wait until endpoint is recovered before > read or write oprations. > > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > --- > drivers/usb/early/xhci-dbc.c | 36 ++++++++++++++++++++++++++++++++++++ > 1 file changed, 36 insertions(+) > > diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c > index c81df40..344d93e 100644 > --- a/drivers/usb/early/xhci-dbc.c > +++ b/drivers/usb/early/xhci-dbc.c > @@ -1163,6 +1163,37 @@ static int xdbc_wait_until_dbc_configured(void) > return -ETIMEDOUT; > } > > +static int xdbc_wait_until_epstall_cleared(bool read) > +{ > + int timeout = 0; > + > + if (read) { > + do { > + if (!(readl(&xdbcp->xdbc_reg->control) & CTRL_HIT)) { > + xdbcp->in_ep_state = EP_RUNNING; > + > + return 0; > + } > + > + xdbcp->in_ep_state = EP_HALTED; > + xdbc_udelay(10); > + } while (timeout++ < XDBC_LOOPS); > + } else { > + do { > + if (!(readl(&xdbcp->xdbc_reg->control) & CTRL_HOT)) { > + xdbcp->out_ep_state = EP_RUNNING; > + > + return 0; > + } > + > + xdbcp->out_ep_state = EP_HALTED; > + xdbc_udelay(10); > + } while (timeout++ < XDBC_LOOPS); > + } > + > + return -ETIMEDOUT; > +} >
how about something like:
enum xdbc_ep_state *ep_state; u32 halt_bit;
if (read) { ep_state = &xdbcp->in_ep_state halt_bit = CTRL_HIT } else { ep_state = &xdbcp->out_ep_state halt_bit = CTRL_HOT } do { if (!(readl(..) & halt_bit)) { *ep_state = EP_RUNNING; return 0; } *ep_state = EP_HALTED; delay() } while (..)
+ > static int xdbc_bulk_transfer(void *data, int size, int loops, bool read) > { > u64 addr; > @@ -1182,6 +1213,11 @@ static int xdbc_bulk_transfer(void *data, int size, int loops, bool read) > return -EPERM; > } > > + if (xdbc_wait_until_epstall_cleared(read)) { > + xdbc_trace("%s: endpoint not ready\n", __func__); > + return -EPERM;
Is -EPERM appropriate here? Not sure about what error codes the device side is using, but usually HALT is set due to some Data buffer/transmission/TRB error. In this case the failure is that debug host failed to send a clearFeature(EP_HALT) request in time.
-Mathias
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