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- To: <quic_wcheng@xxxxxxxxxxx>, <srinivas.kandagatla@xxxxxxxxxx>, <mathias.nyman@xxxxxxxxx>, <perex@xxxxxxxx>, <broonie@xxxxxxxxxx>, <lgirdwood@xxxxxxxxx>, <krzysztof.kozlowski+dt@xxxxxxxxxx>, <agross@xxxxxxxxxx>, <Thinh.Nguyen@xxxxxxxxxxxx>, <bgoswami@xxxxxxxxxxx>, <andersson@xxxxxxxxxx>, <robh+dt@xxxxxxxxxx>, <gregkh@xxxxxxxxxxxxxxxxxxx>, <tiwai@xxxxxxxx>
- Subject: Re: [PATCH v3 02/28] usb: xhci: Add XHCI APIs to support USB offloading
- From: <Claudiu.Beznea@xxxxxxxxxxxxx>
- Date: Fri, 10 Mar 2023 12:17:30 +0000
- Cc: linux-kernel@xxxxxxxxxxxxxxx, linux-arm-msm@xxxxxxxxxxxxxxx, alsa-devel@xxxxxxxxxxxxxxxx, devicetree@xxxxxxxxxxxxxxx, linux-usb@xxxxxxxxxxxxxxx, quic_jackp@xxxxxxxxxxx, quic_plai@xxxxxxxxxxx
- In-reply-to: <20230308235751.495-3-quic_wcheng@quicinc.com>
- References: <20230308235751.495-1-quic_wcheng@quicinc.com> <20230308235751.495-3-quic_wcheng@quicinc.com>
- User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1
On 09.03.2023 01:57, Wesley Cheng wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Some use cases, such as USB audio offloading, will allow for a DSP to take > over issuing USB transfers to the host controller. In order for the DSP to > submit transfers for a particular endpoint, and to handle its events, the > client driver will need to query for some parameters allocated by XHCI. > > - XHCI secondary interrupter event ring address > - XHCI transfer ring address (for a particular EP) > - Stop endpoint command API > > Once the resources are handed off to the DSP, the offload begins, and the > main processor can enter idle. When stopped, since there are no URBs > submitted from the main processor, the client will just issue a stop > endpoint command to halt any pending transfers. > > Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx> > --- > drivers/usb/host/xhci.c | 130 ++++++++++++++++++++++++++++++++++ > include/linux/usb/xhci-intr.h | 8 +++ > 2 files changed, 138 insertions(+) > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index 88435b9cd66e..5c6b3d8f834c 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -1603,6 +1603,136 @@ static int xhci_check_args(struct usb_hcd *hcd, struct usb_device *udev, > return 1; > } > > +int xhci_stop_endpoint(struct usb_device *udev, > + struct usb_host_endpoint *ep) > +{ > + struct usb_hcd *hcd = bus_to_hcd(udev->bus); > + struct xhci_hcd *xhci = hcd_to_xhci(hcd); > + unsigned int ep_index; > + struct xhci_virt_device *virt_dev; > + struct xhci_command *cmd; > + unsigned long flags; > + int ret = 0; No need to initialize it. > + > + ret = xhci_check_args(hcd, udev, ep, 1, true, __func__); > + if (ret <= 0) > + return ret; > + > + cmd = xhci_alloc_command(xhci, true, GFP_NOIO); > + if (!cmd) > + return -ENOMEM; > + > + spin_lock_irqsave(&xhci->lock, flags); > + virt_dev = xhci->devs[udev->slot_id]; > + if (!virt_dev) { > + ret = -ENODEV; > + goto err; > + } > + > + ep_index = xhci_get_endpoint_index(&ep->desc); > + if (virt_dev->eps[ep_index].ring && > + virt_dev->eps[ep_index].ring->dequeue) { > + ret = xhci_queue_stop_endpoint(xhci, cmd, udev->slot_id, > + ep_index, 0); > + if (ret) > + goto err; > + > + xhci_ring_cmd_db(xhci); > + spin_unlock_irqrestore(&xhci->lock, flags); > + > + /* Wait for stop endpoint command to finish */ > + wait_for_completion(cmd->completion); > + > + if (cmd->status == COMP_COMMAND_ABORTED || > + cmd->status == COMP_STOPPED) { ^ usually here go 2nd condition > + xhci_warn(xhci, > + "stop endpoint command timeout for ep%d%s\n", > + usb_endpoint_num(&ep->desc), > + usb_endpoint_dir_in(&ep->desc) ? "in" : "out"); > + ret = -ETIME; > + } } should be aligned with if [ ... ]
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