Streams on the EJ168 do not work as they should. I've spend 2 days trying to get them to work, but without success. The first problem is that when ever you ring the stream-ring doorbell, the controller starts executing trbs at the beginning of the first ring segment, event if it ended somewhere else previously. This can be worked around by allowing enqueing only one td (not a problem with how streams are typically used) and then resetting our copies of the enqueueing en dequeueing pointers on a td completion to match what the controller seems to be doing. This way things seem to start working with uas and instead of being able to complete only the very first scsi command, the scsi core can probe the disk. But then things break later on when td-s get enqueued with more then one trb. The controller does seem to increase its dequeue pointer while executing a stream-ring (data transfer events I inserted for debugging do trigger). However execution seems to stop at the final normal trb of a multi trb td, even if there is a data transfer event inserted after the final trb. The first problem alone is a serious deviation from the spec, and esp. dealing with cancellation would have been very tricky if not outright impossible, but the second problem simply is a deal breaker altogether, so this patch simply disables streams. Note this will cause the usb-storage + uas driver pair to automatically switch to using usb-storage instead of uas on these devices, essentially reverting to the 3.14 and earlier behavior when uas was marked CONFIG_BROKEN. https://bugzilla.redhat.com/show_bug.cgi?id=1121288 https://bugzilla.kernel.org/show_bug.cgi?id=80101 Cc: stable@xxxxxxxxxxxxxxx # 3.15 Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- drivers/usb/host/xhci-pci.c | 4 +++- drivers/usb/host/xhci.c | 3 ++- drivers/usb/host/xhci.h | 2 ++ 3 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index e20520f..464049f 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -143,6 +143,7 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) pdev->device == PCI_DEVICE_ID_ASROCK_P67) { xhci->quirks |= XHCI_RESET_ON_RESUME; xhci->quirks |= XHCI_TRUST_TX_LENGTH; + xhci->quirks |= XHCI_BROKEN_STREAMS; } if (pdev->vendor == PCI_VENDOR_ID_RENESAS && pdev->device == 0x0015) @@ -230,7 +231,8 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id) goto put_usb3_hcd; /* Roothub already marked as USB 3.0 speed */ - if (HCC_MAX_PSA(xhci->hcc_params) >= 4) + if (!(xhci->quirks & XHCI_BROKEN_STREAMS) && + HCC_MAX_PSA(xhci->hcc_params) >= 4) xhci->shared_hcd->can_do_streams = 1; /* USB-2 and USB-3 roothubs initialized, allow runtime pm suspend */ diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 7d02e1b..758bc31 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -3163,7 +3163,8 @@ int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev, num_streams); /* MaxPSASize value 0 (2 streams) means streams are not supported */ - if (HCC_MAX_PSA(xhci->hcc_params) < 4) { + if ((xhci->quirks & XHCI_BROKEN_STREAMS) || + HCC_MAX_PSA(xhci->hcc_params) < 4) { xhci_dbg(xhci, "xHCI controller does not support streams.\n"); return -ENOSYS; } diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 1411069..88b2958 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1558,6 +1558,8 @@ struct xhci_hcd { #define XHCI_PLAT (1 << 16) #define XHCI_SLOW_SUSPEND (1 << 17) #define XHCI_SPURIOUS_WAKEUP (1 << 18) +/* For controllers with a broken beyond repair streams implementation */ +#define XHCI_BROKEN_STREAMS (1 << 19) unsigned int num_active_eps; unsigned int limit_active_eps; /* There are two roothubs to keep track of bus suspend info for */ -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
