Tejas Joglekar <Tejas.Joglekar@xxxxxxxxxxxx> 于2020年5月27日周三 下午7:54写道： > > The Synopsys xHC has an internal TRB cache of size TRB_CACHE_SIZE for > each endpoint. The default value for TRB_CACHE_SIZE is 16 for SS and 8 > for HS. The controller loads and updates the TRB cache from the > transfer ring in system memory whenever the driver issues a start > transfer or update transfer command. > > For chained TRBs, the Synopsys xHC requires that the total amount of > bytes for all TRBs loaded in the TRB cache be greater than or equal to > 1 MPS. Or the chain ends within the TRB cache (with a last TRB). > > If this requirement is not met, the controller will not be able to > send or receive a packet and it will hang causing a driver timeout and > error. Hi Tejas Joglekar I am debugging a similar issue on Synipsys XHC, it's not the same case but I am wondering if it also linked to this HW limitation. My Synopsys XHC based host enable UAS, when enumerates a UAS HDD, one BULK-IN EP with stream enabled will not generate event for trb(with stream ID 1) after a 16/4096 bytes(with stream ID 2) finished in previous trb. If I change the last OK urb/trb's buffer length from 4096 to 512, the issue will gone. following is the sequence of the question EP-IN: <idle>-0 [000] d.h1 154.961710: xhci_urb_giveback: ep3in-bulk: urb ffff0001775f6f00 pipe 3221324672 slot 1 length 36/36 sgs 1/1 stream 1 flags 00040200 <idle>-0 [000] d.h1 154.962023: xhci_urb_giveback: ep3in-bulk: urb ffff000177d00400 pipe 3221324672 slot 1 length 96/96 sgs 1/1 stream 1 flags 00040200 <idle>-0 [000] d.h1 154.970395: xhci_urb_giveback: ep3in-bulk: urb ffff000177d00400 pipe 3221324672 slot 1 length 11/255 sgs 1/1 stream 1 flags 00040200 <idle>-0 [000] d.h1 154.970562: xhci_urb_giveback: ep3in-bulk: urb ffff000177d00400 pipe 3221324672 slot 1 length 20/255 sgs 1/1 stream 1 flags 00040200 <idle>-0 [000] d.h1 154.970786: xhci_urb_giveback: ep3in-bulk: urb ffff000177d00400 pipe 3221324672 slot 1 length 60/255 sgs 1/1 stream 1 flags 00040200 <idle>-0 [000] d.h1 155.851600: xhci_urb_giveback: ep3in-bulk: urb ffff000177d00200 pipe 3221324672 slot 1 length 16/4096 sgs 1/1 stream 2 flags 00040200 /* then the next ep3-in trb will not generate event and stopped, so driver timeout in the end */ kworker/u8:2-349 [003] d..3 155.851987: xhci_urb_enqueue: ep3in-bulk: urb ffff000170492400 pipe 3221324672 slot 1 length 0/32 sgs 1/1 stream 1 flags 00040200 kworker/u8:2-349 [003] d..4 155.851989: xhci_queue_trb: STREAM: Buffer 00000000c19cf000 length 32 TD size 0 intr 0 type 'Normal' flags b:i:I:c:s:I:e:c kworker/u8:2-349 [003] d..4 155.851991: xhci_inc_enq: STREAM ffff000177f86f80: enq 0x00000000be0eb060(0x00000000be0eb000) deq 0x00000000be0eb050(0x00000000be0eb000) segs 2 stream 1 free_trbs 508 bounce 1024 cycle 1 Do you have any ideas? thanks Li Jun > > This patch set adds logic to the XHCI driver to detect and prevent this > from happening along with the quirk to enable this logic for Synopsys > HAPS platform. > > Based on Mathias's feedback on previous implementation where consolidation > was done in TRB cache, with this patch series the implementation is done > during mapping of the URB by consolidating the SG list into a temporary > buffer if the SG list buffer sizes within TRB_CACHE_SIZE is less than MPS. > > Changes since v2: > - Modified the xhci_unmap_temp_buffer function to unmap dma and clear > the dma flag > - Removed RFC tag > > Changes since v1: > - Comments from Greg are addressed on [PATCH 4/4] and [PATCH 1/4] > - Renamed the property and quirk as in other patches based on [PATCH 1/4] > > Tejas Joglekar (4): > dt-bindings: usb: Add documentation for SG trb cache size quirk > usb: xhci: Set quirk for XHCI_SG_TRB_CACHE_SIZE_QUIRK > usb: dwc3: Add device property sgl-trb-cache-size-quirk > usb: xhci: Use temporary buffer to consolidate SG > > Documentation/devicetree/bindings/usb/dwc3.txt | 4 + > Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 + > drivers/usb/dwc3/core.c | 2 + > drivers/usb/dwc3/core.h | 2 + > drivers/usb/dwc3/dwc3-haps.c | 1 + > drivers/usb/dwc3/host.c | 6 +- > drivers/usb/host/xhci-pci.c | 3 + > drivers/usb/host/xhci-plat.c | 4 + > drivers/usb/host/xhci-ring.c | 2 +- > drivers/usb/host/xhci.c | 135 +++++++++++++++++++++ > drivers/usb/host/xhci.h | 5 + > 11 files changed, 165 insertions(+), 2 deletions(-) > > -- > 2.11.0 >
