On 15-12-23 06:12 pm, Greg Kroah-Hartman wrote:
On Tue, Dec 12, 2023 at 04:55:20PM +0530, Prashanth K wrote:
Upstream commit bac1ec551434 ("usb: xhci: Set quirk for
XHCI_SG_TRB_CACHE_SIZE_QUIRK") introduced a new quirk in XHCI
which fixes XHC timeout, which was seen on synopsys XHCs while
using SG buffers. But the support for this quirk isn't present
in the DWC3 layer.
We will encounter this XHCI timeout/hung issue if we run iperf
loopback tests using RTL8156 ethernet adaptor on DWC3 targets
with scatter-gather enabled. This gets resolved after enabling
the XHCI_SG_TRB_CACHE_SIZE_QUIRK. This patch enables it using
the xhci device property since its needed for DWC3 controller.
In Synopsys DWC3 databook,
Table 9-3: xHCI Debug Capability Limitations
Chained TRBs greater than TRB cache size: The debug capability
driver must not create a multi-TRB TD that describes smaller
than a 1K packet that spreads across 8 or more TRBs on either
the IN TR or the OUT TR.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>
What commit id does this fix?
This doesn't fix any commit as such, but adds the support for
XHCI_SG_TRB_CACHE_SIZE_QUIRK (which is present in XHCI layer) to DWC3
layer. I have CC'ed stable kernel for this to be back-ported to older
kernels (#5.11).
---
drivers/usb/dwc3/host.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 61f57fe5bb78..31a496233d87 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -89,6 +89,8 @@ int dwc3_host_init(struct dwc3 *dwc)
memset(props, 0, sizeof(struct property_entry) * ARRAY_SIZE(props));
+ props[prop_idx++] = PROPERTY_ENTRY_BOOL("xhci-sg-trb-cache-size-quirk");
And this is ok if the entry is not present?
We are intending to use this quirk for all the dwc3 based devices since
the DWC3 XHC needs it. If the entry is not present then we will hit
stall if certain conditions aren't met (have mentioned the condition in
commit text).
Thanks,
Prashanth K
