[PATCH 0/2] xhci fixes for usb-linus

[PATCH 0/2] xhci fixes for usb-linus

[Mathias Nyman]

Hi Greg

A couple xhci fixes for 6.4
Fixing a S3 resume issue on AMD hosts, and a flaw in calculating free TRBs
in ring buffer which may cause xhci to hog extra memory.

Thanks
Mathias

Mario Limonciello (1):
  xhci-pci: Only run d3cold avoidance quirk for s2idle

Mathias Nyman (1):
  xhci: Fix incorrect tracking of free space on transfer rings

 drivers/usb/host/xhci-pci.c  | 12 ++++++++++--
 drivers/usb/host/xhci-ring.c | 29 ++++++++++++++++++++++++++++-
 drivers/usb/host/xhci.h      |  2 +-
 3 files changed, 39 insertions(+), 4 deletions(-)

-- 
2.25.1

[PATCH 1/2] xhci-pci: Only run d3cold avoidance quirk for s2idle

[Mathias Nyman]

From: Mario Limonciello <mario.limonciello@amd.com>

Donghun reports that a notebook that has an AMD Ryzen 5700U but supports
S3 has problems with USB after resuming from suspend. The issue was
bisected down to commit d1658268e439 ("usb: pci-quirks: disable D3cold on
xhci suspend for s2idle on AMD Renoir").

As this issue only happens on S3, narrow the broken D3cold quirk to only
run in s2idle.

Fixes: d1658268e439 ("usb: pci-quirks: disable D3cold on xhci suspend for s2idle on AMD Renoir")
Reported-and-tested-by: Donghun Yoon <donghun.yoon@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-pci.c | 12 ++++++++++--
 drivers/usb/host/xhci.h     |  2 +-
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index ddb79f23fb3b..79b3691f373f 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/acpi.h>
 #include <linux/reset.h>
+#include <linux/suspend.h>
 
 #include "xhci.h"
 #include "xhci-trace.h"
@@ -387,7 +388,7 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 
 	if (pdev->vendor == PCI_VENDOR_ID_AMD &&
 		pdev->device == PCI_DEVICE_ID_AMD_RENOIR_XHCI)
-		xhci->quirks |= XHCI_BROKEN_D3COLD;
+		xhci->quirks |= XHCI_BROKEN_D3COLD_S2I;
 
 	if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
 		xhci->quirks |= XHCI_LPM_SUPPORT;
@@ -801,9 +802,16 @@ static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
 	 * Systems with the TI redriver that loses port status change events
 	 * need to have the registers polled during D3, so avoid D3cold.
 	 */
-	if (xhci->quirks & (XHCI_COMP_MODE_QUIRK | XHCI_BROKEN_D3COLD))
+	if (xhci->quirks & XHCI_COMP_MODE_QUIRK)
 		pci_d3cold_disable(pdev);
 
+#ifdef CONFIG_SUSPEND
+	/* d3cold is broken, but only when s2idle is used */
+	if (pm_suspend_target_state == PM_SUSPEND_TO_IDLE &&
+	    xhci->quirks & (XHCI_BROKEN_D3COLD_S2I))
+		pci_d3cold_disable(pdev);
+#endif
+
 	if (xhci->quirks & XHCI_PME_STUCK_QUIRK)
 		xhci_pme_quirk(hcd);
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 08d721921b7b..6b690ec91ff3 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1901,7 +1901,7 @@ struct xhci_hcd {
 #define XHCI_DISABLE_SPARSE	BIT_ULL(38)
 #define XHCI_SG_TRB_CACHE_SIZE_QUIRK	BIT_ULL(39)
 #define XHCI_NO_SOFT_RETRY	BIT_ULL(40)
-#define XHCI_BROKEN_D3COLD	BIT_ULL(41)
+#define XHCI_BROKEN_D3COLD_S2I	BIT_ULL(41)
 #define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
 #define XHCI_SUSPEND_RESUME_CLKS	BIT_ULL(43)
 #define XHCI_RESET_TO_DEFAULT	BIT_ULL(44)
-- 
2.25.1

[PATCH 2/2] xhci: Fix incorrect tracking of free space on transfer rings

[Mathias Nyman]

This incorrect tracking caused unnecessary ring expansion in some
usecases which over days of use consume a lot of memory.

xhci driver tries to keep track of free transfer blocks (TRBs) on the
ring buffer, but failed to add back some cancelled transfers that were
turned into no-op operations instead of just moving past them.

This can happen if there are several queued pending transfers which
then are cancelled in reverse order.

Solve this by counting the numer of steps we move the dequeue pointer
once we complete a transfer, and add it to the number of free trbs
instead of just adding the trb number of the current transfer.
This way we ensure we count the no-op trbs on the way as well.

Fixes: 55f6153d8cc8 ("xhci: remove extra loop in interrupt context")
Cc: stable@vger.kernel.org
Reported-by: Miller Hunter <MillerH@hearthnhome.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217242
Tested-by: Miller Hunter <MillerH@hearthnhome.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-ring.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 1ad12d5a4857..2bc82b3a2f98 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -276,6 +276,26 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
 	trace_xhci_inc_enq(ring);
 }
 
+static int xhci_num_trbs_to(struct xhci_segment *start_seg, union xhci_trb *start,
+			    struct xhci_segment *end_seg, union xhci_trb *end,
+			    unsigned int num_segs)
+{
+	union xhci_trb *last_on_seg;
+	int num = 0;
+	int i = 0;
+
+	do {
+		if (start_seg == end_seg && end >= start)
+			return num + (end - start);
+		last_on_seg = &start_seg->trbs[TRBS_PER_SEGMENT - 1];
+		num += last_on_seg - start;
+		start_seg = start_seg->next;
+		start = start_seg->trbs;
+	} while (i++ <= num_segs);
+
+	return -EINVAL;
+}
+
 /*
  * Check to see if there's room to enqueue num_trbs on the ring and make sure
  * enqueue pointer will not advance into dequeue segment. See rules above.
@@ -2140,6 +2160,7 @@ static int finish_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 		     u32 trb_comp_code)
 {
 	struct xhci_ep_ctx *ep_ctx;
+	int trbs_freed;
 
 	ep_ctx = xhci_get_ep_ctx(xhci, ep->vdev->out_ctx, ep->ep_index);
 
@@ -2209,9 +2230,15 @@ static int finish_td(struct xhci_hcd *xhci, struct xhci_virt_ep *ep,
 	}
 
 	/* Update ring dequeue pointer */
+	trbs_freed = xhci_num_trbs_to(ep_ring->deq_seg, ep_ring->dequeue,
+				      td->last_trb_seg, td->last_trb,
+				      ep_ring->num_segs);
+	if (trbs_freed < 0)
+		xhci_dbg(xhci, "Failed to count freed trbs at TD finish\n");
+	else
+		ep_ring->num_trbs_free += trbs_freed;
 	ep_ring->dequeue = td->last_trb;
 	ep_ring->deq_seg = td->last_trb_seg;
-	ep_ring->num_trbs_free += td->num_trbs - 1;
 	inc_deq(xhci, ep_ring);
 
 	return xhci_td_cleanup(xhci, td, ep_ring, td->status);
-- 
2.25.1