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usb: dwc3: host: Set XHCI_SG_TRB_CACHE_SIZE_QUIRK
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commit 817349b upstream.

Upstream commit bac1ec5 ("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@vger.kernel.org #5.11
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20240116055816.1169821-2-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Prashanth K authored and gregkh committed Feb 16, 2024
1 parent 041cb58 commit f2cf6db
Showing 1 changed file with 3 additions and 1 deletion.
4 changes: 3 additions & 1 deletion drivers/usb/dwc3/host.c
Original file line number Diff line number Diff line change
Expand Up @@ -66,7 +66,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)

int dwc3_host_init(struct dwc3 *dwc)
{
struct property_entry props[4];
struct property_entry props[5];
struct platform_device *xhci;
int ret, irq;
int prop_idx = 0;
Expand Down Expand Up @@ -94,6 +94,8 @@ 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");

if (dwc->usb3_lpm_capable)
props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb3-lpm-capable");

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