From: Niklas Neronin <niklas.neronin@linux.intel.com>
To: stable@vger.kernel.org, gregkh@linuxfoundation.org
Cc: mathias.nyman@linux.intel.com,
Niklas Neronin <niklas.neronin@linux.intel.com>,
Wolfgang Walter <linux@stwm.de>
Subject: [PATCH] Revert "usb: xhci: remove option to change a default ring's TRB cycle bit"
Date: Tue, 30 Sep 2025 15:22:51 +0200 [thread overview]
Message-ID: <20250930132251.945081-1-niklas.neronin@linux.intel.com> (raw)
Revert 9b28ef1e4cc0 [ Upstream commit e1b0fa863907 ], it causes regression
in 6.12.49 stable, no issues in upstream.
Commit 9b28ef1e4cc0 ("usb: xhci: remove option to change a default ring's
TRB cycle bit") introduced a regression in 6.12.49 stable kernel.
The original commit was never intended for stable kernels, but was added
as a dependency for commit a5c98e8b1398 ("xhci: dbc: Fix full DbC transfer
ring after several reconnects").
Since this commit is more of an optimization, revert it and solve the
dependecy by modifying one line in xhci_dbc_ring_init(). Specifically,
commit a5c98e8b1398 ("xhci: dbc: Fix full DbC transfer ring after several
reconnects") moved function call xhci_initialize_ring_info() into a
separate function. To resolve the dependency, the arguments for this
function call are also reverted.
Closes: https://lore.kernel.org/stable/01b8c8de46251cfaad1329a46b7e3738@stwm.de/
Tested-by: Wolfgang Walter <linux@stwm.de>
Cc: stable@vger.kernel.org # v6.12.49
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
---
drivers/usb/host/xhci-dbgcap.c | 2 +-
drivers/usb/host/xhci-mem.c | 50 ++++++++++++++++++----------------
drivers/usb/host/xhci.c | 2 +-
drivers/usb/host/xhci.h | 6 ++--
4 files changed, 33 insertions(+), 27 deletions(-)
diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index 1fcc9348dd43..123506681ef0 100644
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -458,7 +458,7 @@ static void xhci_dbc_ring_init(struct xhci_ring *ring)
trb->link.segment_ptr = cpu_to_le64(ring->first_seg->dma);
trb->link.control = cpu_to_le32(LINK_TOGGLE | TRB_TYPE(TRB_LINK));
}
- xhci_initialize_ring_info(ring);
+ xhci_initialize_ring_info(ring, 1);
}
static int xhci_dbc_reinit_ep_rings(struct xhci_dbc *dbc)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index c9694526b157..f0ed38da6a0c 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -27,12 +27,14 @@
* "All components of all Command and Transfer TRBs shall be initialized to '0'"
*/
static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci,
+ unsigned int cycle_state,
unsigned int max_packet,
unsigned int num,
gfp_t flags)
{
struct xhci_segment *seg;
dma_addr_t dma;
+ int i;
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
seg = kzalloc_node(sizeof(*seg), flags, dev_to_node(dev));
@@ -54,6 +56,11 @@ static struct xhci_segment *xhci_segment_alloc(struct xhci_hcd *xhci,
return NULL;
}
}
+ /* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
+ if (cycle_state == 0) {
+ for (i = 0; i < TRBS_PER_SEGMENT; i++)
+ seg->trbs[i].link.control = cpu_to_le32(TRB_CYCLE);
+ }
seg->num = num;
seg->dma = dma;
seg->next = NULL;
@@ -131,14 +138,6 @@ static void xhci_link_rings(struct xhci_hcd *xhci, struct xhci_ring *ring,
chain_links = xhci_link_chain_quirk(xhci, ring->type);
- /* If the cycle state is 0, set the cycle bit to 1 for all the TRBs */
- if (ring->cycle_state == 0) {
- xhci_for_each_ring_seg(ring->first_seg, seg) {
- for (int i = 0; i < TRBS_PER_SEGMENT; i++)
- seg->trbs[i].link.control |= cpu_to_le32(TRB_CYCLE);
- }
- }
-
next = ring->enq_seg->next;
xhci_link_segments(ring->enq_seg, first, ring->type, chain_links);
xhci_link_segments(last, next, ring->type, chain_links);
@@ -288,7 +287,8 @@ void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring)
kfree(ring);
}
-void xhci_initialize_ring_info(struct xhci_ring *ring)
+void xhci_initialize_ring_info(struct xhci_ring *ring,
+ unsigned int cycle_state)
{
/* The ring is empty, so the enqueue pointer == dequeue pointer */
ring->enqueue = ring->first_seg->trbs;
@@ -302,7 +302,7 @@ void xhci_initialize_ring_info(struct xhci_ring *ring)
* New rings are initialized with cycle state equal to 1; if we are
* handling ring expansion, set the cycle state equal to the old ring.
*/
- ring->cycle_state = 1;
+ ring->cycle_state = cycle_state;
/*
* Each segment has a link TRB, and leave an extra TRB for SW
@@ -317,6 +317,7 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
struct xhci_segment **first,
struct xhci_segment **last,
unsigned int num_segs,
+ unsigned int cycle_state,
enum xhci_ring_type type,
unsigned int max_packet,
gfp_t flags)
@@ -327,7 +328,7 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
chain_links = xhci_link_chain_quirk(xhci, type);
- prev = xhci_segment_alloc(xhci, max_packet, num, flags);
+ prev = xhci_segment_alloc(xhci, cycle_state, max_packet, num, flags);
if (!prev)
return -ENOMEM;
num++;
@@ -336,7 +337,8 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
while (num < num_segs) {
struct xhci_segment *next;
- next = xhci_segment_alloc(xhci, max_packet, num, flags);
+ next = xhci_segment_alloc(xhci, cycle_state, max_packet, num,
+ flags);
if (!next)
goto free_segments;
@@ -361,8 +363,9 @@ static int xhci_alloc_segments_for_ring(struct xhci_hcd *xhci,
* Set the end flag and the cycle toggle bit on the last segment.
* See section 4.9.1 and figures 15 and 16.
*/
-struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci, unsigned int num_segs,
- enum xhci_ring_type type, unsigned int max_packet, gfp_t flags)
+struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
+ unsigned int num_segs, unsigned int cycle_state,
+ enum xhci_ring_type type, unsigned int max_packet, gfp_t flags)
{
struct xhci_ring *ring;
int ret;
@@ -380,7 +383,7 @@ struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci, unsigned int num_segs,
return ring;
ret = xhci_alloc_segments_for_ring(xhci, &ring->first_seg, &ring->last_seg, num_segs,
- type, max_packet, flags);
+ cycle_state, type, max_packet, flags);
if (ret)
goto fail;
@@ -390,7 +393,7 @@ struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci, unsigned int num_segs,
ring->last_seg->trbs[TRBS_PER_SEGMENT - 1].link.control |=
cpu_to_le32(LINK_TOGGLE);
}
- xhci_initialize_ring_info(ring);
+ xhci_initialize_ring_info(ring, cycle_state);
trace_xhci_ring_alloc(ring);
return ring;
@@ -418,8 +421,8 @@ int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring,
struct xhci_segment *last;
int ret;
- ret = xhci_alloc_segments_for_ring(xhci, &first, &last, num_new_segs, ring->type,
- ring->bounce_buf_len, flags);
+ ret = xhci_alloc_segments_for_ring(xhci, &first, &last, num_new_segs, ring->cycle_state,
+ ring->type, ring->bounce_buf_len, flags);
if (ret)
return -ENOMEM;
@@ -629,7 +632,8 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
stream_info->stream_rings[cur_stream] =
- xhci_ring_alloc(xhci, 2, TYPE_STREAM, max_packet, mem_flags);
+ xhci_ring_alloc(xhci, 2, 1, TYPE_STREAM, max_packet,
+ mem_flags);
cur_ring = stream_info->stream_rings[cur_stream];
if (!cur_ring)
goto cleanup_rings;
@@ -970,7 +974,7 @@ int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id,
}
/* Allocate endpoint 0 ring */
- dev->eps[0].ring = xhci_ring_alloc(xhci, 2, TYPE_CTRL, 0, flags);
+ dev->eps[0].ring = xhci_ring_alloc(xhci, 2, 1, TYPE_CTRL, 0, flags);
if (!dev->eps[0].ring)
goto fail;
@@ -1453,7 +1457,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
/* Set up the endpoint ring */
virt_dev->eps[ep_index].new_ring =
- xhci_ring_alloc(xhci, 2, ring_type, max_packet, mem_flags);
+ xhci_ring_alloc(xhci, 2, 1, ring_type, max_packet, mem_flags);
if (!virt_dev->eps[ep_index].new_ring)
return -ENOMEM;
@@ -2262,7 +2266,7 @@ xhci_alloc_interrupter(struct xhci_hcd *xhci, unsigned int segs, gfp_t flags)
if (!ir)
return NULL;
- ir->event_ring = xhci_ring_alloc(xhci, segs, TYPE_EVENT, 0, flags);
+ ir->event_ring = xhci_ring_alloc(xhci, segs, 1, TYPE_EVENT, 0, flags);
if (!ir->event_ring) {
xhci_warn(xhci, "Failed to allocate interrupter event ring\n");
kfree(ir);
@@ -2468,7 +2472,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
goto fail;
/* Set up the command ring to have one segments for now. */
- xhci->cmd_ring = xhci_ring_alloc(xhci, 1, TYPE_COMMAND, 0, flags);
+ xhci->cmd_ring = xhci_ring_alloc(xhci, 1, 1, TYPE_COMMAND, 0, flags);
if (!xhci->cmd_ring)
goto fail;
xhci_dbg_trace(xhci, trace_xhci_dbg_init,
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3970ec831b8c..abbf89e82d01 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -769,7 +769,7 @@ static void xhci_clear_command_ring(struct xhci_hcd *xhci)
seg->trbs[TRBS_PER_SEGMENT - 1].link.control &= cpu_to_le32(~TRB_CYCLE);
}
- xhci_initialize_ring_info(ring);
+ xhci_initialize_ring_info(ring, 1);
/*
* Reset the hardware dequeue pointer.
* Yes, this will need to be re-written after resume, but we're paranoid
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index b2aeb444daaf..b4fa8e7e4376 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1803,12 +1803,14 @@ void xhci_slot_copy(struct xhci_hcd *xhci,
int xhci_endpoint_init(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev,
struct usb_device *udev, struct usb_host_endpoint *ep,
gfp_t mem_flags);
-struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci, unsigned int num_segs,
+struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
+ unsigned int num_segs, unsigned int cycle_state,
enum xhci_ring_type type, unsigned int max_packet, gfp_t flags);
void xhci_ring_free(struct xhci_hcd *xhci, struct xhci_ring *ring);
int xhci_ring_expansion(struct xhci_hcd *xhci, struct xhci_ring *ring,
unsigned int num_trbs, gfp_t flags);
-void xhci_initialize_ring_info(struct xhci_ring *ring);
+void xhci_initialize_ring_info(struct xhci_ring *ring,
+ unsigned int cycle_state);
void xhci_free_endpoint_ring(struct xhci_hcd *xhci,
struct xhci_virt_device *virt_dev,
unsigned int ep_index);
--
2.50.1
next reply other threads:[~2025-09-30 13:25 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-30 13:22 Niklas Neronin [this message]
2025-09-30 13:51 ` [PATCH] Revert "usb: xhci: remove option to change a default ring's TRB cycle bit" Mathias Nyman
2025-09-30 14:04 ` Greg KH
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