A ring consists of a list of segments, each containing a specific number of
TRBs. The xhci driver allocates and initializes ring segments and TRBs in
the same functions. This combined allocation and initialization process
leads to an issue where, after hibernation (S4 state), the xhci driver
frees all its memory and re-creates the rings, segments, and TRBs from
scratch.
Move all default ring segment initialization into function
xhci_initialize_ring_segments(). This function can be called to
reinitialize a ring without freeing and reallocating it.
Since xhci_alloc_segments_for_ring() no longer initializes segment TRBs,
xhci_initialize_ring_segments() is added to xhci_ring_expansion(). This
results in the last segment of the source ring having the 'LINK_TOGGLE'
bit set. Therefore, if the last source ring segment is not the last in
the destination ring, the 'LINK_TOGGLE' bit must be cleared.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241106101459.775897-17-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prepare for splitting ring segments allocation and initialization by
reworking the xhci_link_segments() function. Segment linking and ring type
checks are moved out of xhci_link_segments(), and the function is renamed
to "xhci_set_link_trb()".
The goal is to keep ring linking within xhci_alloc_segments_for_ring() and
move initialization into a separate function.
Additionally, reorder and simplify xhci_set_link_trb() for better
readability.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241106101459.775897-16-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The segment list is only relevant within the context of the ring.
Thus, it is more logical to pass the ring itself when freeing all segments
from a ring, rather than passing the ring list.
Rename the function to "xhci_ring_segments_free" to align with the naming
convention of xhci_segment_free().
To make the freeing process more intuitive, free segments sequentially
from start to end (i.e., 0, 1, 2, 3, ...) instead of freeing the first
segment last (i.e., 1, 2, 3, ... 0).
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241106101459.775897-14-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The TRB cycle bit indicates TRB ownership by the Host Controller (HC) or
Host Controller Driver (HCD). New rings are initialized with 'cycle_state'
equal to one, and all its TRBs' cycle bits are set to zero. When handling
ring expansion, set the source ring cycle bits to the same value as the
destination ring.
Move the cycle bit setting from xhci_segment_alloc() to xhci_link_rings(),
and remove the 'cycle_state' argument from xhci_initialize_ring_info().
The xhci_segment_alloc() function uses kzalloc_node() to allocate segments,
ensuring that all TRB cycle bits are initialized to zero.
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241106101459.775897-12-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This quirk is for the controller that has a limitation in supporting
separate ERSTBA_HI and ERSTBA_LO programming. It's supported when
the ERSTBA is programmed ERSTBA_HI before ERSTBA_LO. That's because
the internal initialization of event ring fetches the
"Event Ring Segment Table Entry" based on the indication of ERSTBA_LO
written.
Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
Link: https://lore.kernel.org/r/1718019553-111939-3-git-send-email-dh10.jung@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Check if requested segments ('segs' or 'ERST_DEFAULT_SEGS') exceeds the
maximum amount ERST supports.
When 'segs' is '0', 'ERST_DEFAULT_SEGS' is used instead. But both values
may not exceed ERST max.
Macro 'ERST_MAX_SEGS' is renamed to 'ERST_DEFAULT_SEGS'. The new name
better represents the macros, which is the number of Event Ring segments
to allocate, when the amount is not specified.
Additionally, rename and change xhci_create_secondary_interrupter()'s
argument 'int num_segs' to 'unsigned int segs'. This makes it the same
as its counter part in xhci_alloc_interrupter().
Fixes: c99b38c412 ("xhci: add support to allocate several interrupters")
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240429140245.3955523-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Port capability flags for USB2 ports have been cached in an
u32 xhci->ext_caps[] array long before the driver had struct xhci_port
and struct xhci_port_cap structures.
Move these cached USB2 port capability values together with the other
port capability values into struct xhci_port_cap cability structure.
This also gets rid of the cumbersome way of mapping port to USB2
capability based on portnum as each port has a pointer to its capability
structure.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240429140245.3955523-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Refactor the code to improve readability by using
'xhci_free_segments_for_ring()' function for freeing ring segments.
This replaces the custom while loop previously used within
'xhci_ring_expansion()' and 'xhci_alloc_segments_for_ring()'.
Slightly modify 'xhci_free_segments_for_ring()' to handle lists
which do not loop. This makes it possible to use it in error
paths of 'xhci_alloc_segments_for_ring()'.
This change also prepares for switching the custom xhci linked segment
list into to more standard list.h lists.
[minor commit message rewording -Mathias]
Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240229141438.619372-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Slot ID is a index of a virtual device in struct 'xhci_hcd->devs[]'.
Previously, to get the slot ID associated with a port, we had to loop
through all devices and compare ports, which is very inefficient.
Instead, the slot ID (of the device which is directly connected to the
port), is added to the its corresponding 'xhci_port' struct. As a result,
finding the port's device is quick and easy.
Function 'xhci_find_slot_id_by_port()' is removed, as it is no longer
needed.
Signed-off-by: Niklas Neronin <niklas.neronin@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240229141438.619372-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Variables real & fake port do not convey their purpose, thus they are
replaced with a pointer to the root hub port 'struct xhci_port *rhub_port'.
'rhub_port' contains real & fake ports in zero-based format, which happens
to be more widely used inside the xHCI driver:
- 'real_port' is ('rhub_port->hw_portnum' + 1)
- 'fake_port' is ('rhub_port->hcd_portnum' + 1)
One reason for real port being one-based, is to signal other functions in
case struct 'xhci_virt_device' initialization failed, in this case the
value will remain 0. This is no longer needed, instead we check whether
or not 'rhub_port' is 'NULL'.
Signed-off-by: Niklas Neronin <niklas.neronin@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240229141438.619372-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xHC hardware needs to know which roothub port a USB device is attached to
when controlling the device, so the xHCI driver stores in each device the
roothub port which it's connected behind. This is done with two different
port index values, the 'real_port' which is an index to the xHC hardware
port register array, and the 'fake_port' which is the per hub port index
used by the hub driver.
Instead of finding real & fake port separately, find the root hub port
'xhci_port' structure which contains both real & fake port values:
- 'real_port' is ('hw_portnum' + 1)
- 'fake_port' is ('hcd_portnum' + 1)
i.e. real & fake port are 'hw_portnum' & 'hcd_portnum' in one-based
format.
The 'xhci_port' structure is a better way to refer to roothub ports than
the 'real_port' & 'fake_port'. As a result, these port indexes are slated
to be replaced with a direct pointer to the root hub port. This patch
setups the ground work for the future changes.
Signed-off-by: Niklas Neronin <niklas.neronin@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240229141438.619372-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
isoc_bei_interval is used to balance how often completed isochronous
events cause interrupts. If interval is too large then the event ring
may fill up before the completed isoc TRBs are handled.
isoc_bei_interval is tuned based on how full the event ring is.
isoc_bei_interval variable needs to be per interrupter as
with several interrupters each one has its own event ring.
move isoc_bei_interval variable to the interrupter structure.
if a secondary interrupter does not care about this feature then
keep isoc_bei_interval 0.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20240217001017.29969-4-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modify the XHCI drivers to accommodate for handling multiple event rings in
case there are multiple interrupters. Add the required APIs so clients are
able to allocate/request for an interrupter ring, and pass this information
back to the client driver. This allows for users to handle the resource
accordingly, such as passing the event ring base address to an audio DSP.
There is no actual support for multiple MSI/MSI-X vectors.
[export xhci_initialize_ring_info() -wcheng]
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20240102214549.22498-2-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- The HCD address_device callback now accepts a user-defined timeout value
in milliseconds, providing better control over command execution times.
- The default timeout value for the address_device command has been set
to 5000 ms, aligning with the USB 3.2 specification. However, this
timeout can be adjusted as needed.
- The xhci_setup_device function has been updated to accept the timeout
value, allowing it to specify the maximum wait time for the command
operation to complete.
- The hub driver has also been updated to accommodate the newly added
timeout parameter during the SET_ADDRESS request.
Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Reviewed-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231027152029.104363-1-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current function that both removes and frees an interrupter isn't
optimal when using several interrupters. The array of interrupters need
to be protected with a lock while removing interrupters, but the default
xhci spin lock can't be used while freeing the interrupters event ring
segment table as dma_free_coherent() should be called with IRQs enabled.
There is no need to free the interrupter under the lock, so split this
code into separate unlocked free part, and a lock protected remove part.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231019102924.2797346-17-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Initial xhci_ring allocation has just been amended to assign a
monotonically increasing number to each ring segment.
However rings may be expanded after initial allocation.
So number newly inserted segments starting from the preceding segment in
the ring and renumber all segments succeeding the newly inserted ones.
This is not a fix because ring expansion currently isn't done on the
Event Ring and that's the only ring type using the segment number.
It's just in preparation for when either Event Ring expansion is added
or when other ring types start making use of the segment number.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231019102924.2797346-7-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Users have reported log spam created by "Event Ring Full" xHC event
TRBs. These are caused by interrupt latency in conjunction with a very
busy set of devices on the bus. The errors are benign, but throughput
will suffer as the xHC will pause processing of transfers until the
Event Ring is drained by the kernel.
Commit dc0ffbea57 ("usb: host: xhci: update event ring dequeue pointer
on purpose") mitigated the issue by advancing the Event Ring Dequeue
Pointer already after half a segment has been processed. Nevertheless,
providing a larger Event Ring would be useful to cope with load peaks.
Expand the number of event TRB slots available by increasing the number
of Event Ring segments in the ERST.
Controllers have a hardware-defined limit as to the number of ERST
entries they can process, but with up to 32k it can be excessively high
(sec 5.3.4). So cap the actual number at 2 (configurable through the
ERST_MAX_SEGS macro), which seems like a reasonable quantity. It is
supported by any xHC because the limit in the HCSPARAMS2 register is
defined as a power of 2. Renesas uPD720201 and VIA VL805 controllers
do not support more than 2 ERST entries.
An alternative to increasing the number of Event Ring segments would be
an increase of the segment size. But that requires allocating multiple
contiguous pages, which may be impossible if memory is fragmented.
Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231019102924.2797346-6-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When using more than one Event Ring segment (ERSTSZ > 1), software shall
set the DESI bits in the ERDP register to the number of the segment to
which the upper ERDP bits are pointing. The xHC may use the DESI bits
as a shortcut to determine whether it needs to check for an Event Ring
Full condition: If it's enqueueing events in a different segment, it
need not compare its internal Enqueue Pointer with the Dequeue Pointer
in the upper bits of the ERDP register (sec 5.5.2.3.3).
Not setting the DESI bits correctly can result in the xHC enqueueing
events past the Dequeue Pointer. On Renesas uPD720201 host controllers,
incorrect DESI bits cause an interrupt storm. For comparison, VIA VL805
host controllers do not exhibit such problems. Perhaps they do not take
advantage of the optimization afforded by the DESI bits.
To fix the issue, assign the segment number to each struct xhci_segment
in xhci_segment_alloc(). When advancing the Dequeue Pointer in
xhci_update_erst_dequeue(), write the segment number to the DESI bits.
On driver probe, set the DESI bits to zero in xhci_set_hc_event_deq() as
processing starts in segment 0. Likewise on driver teardown, clear the
DESI bits to zero in xhci_free_interrupter() when clearing the upper
bits of the ERDP register. Previously those functions (incorrectly)
treated the DESI bits as if they're declared RsvdP.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20231019102924.2797346-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xhci_add_interrupter() erroneously preserves only the lowest 4 bits when
writing the ERSTBA register, not the lowest 6 bits. Fix it.
Migrate the ERST_BASE_RSVDP macro to the modern GENMASK_ULL() syntax to
avoid a u64 cast.
This was previously fixed by commit 8c1cbec9db ("xhci: fix event ring
segment table related masks and variables in header"), but immediately
undone by commit b17a57f89f ("xhci: Refactor interrupter code for
initial multi interrupter support.").
Fixes: b17a57f89f ("xhci: Refactor interrupter code for initial multi interrupter support.")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v6.3+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230915143108.1532163-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wireless USB has long been defunct, and kernel support for it was
removed in 2020 by commit caa6772db4 ("Staging: remove wusbcore and
UWB from the kernel tree.").
Nevertheless, some vestiges of the old implementation still clutter up
the USB subsystem and one or two other places. Let's get rid of them
once and for all.
The only parts still left are the user-facing APIs in
include/uapi/linux/usb/ch9.h. (There are also a couple of misleading
instances, such as the Sierra Wireless USB modem, which is a USB modem
made by Sierra Wireless.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/b4f2710f-a2de-4fb0-b50f-76776f3a961b@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Trying to keep track of free trbs in a ring by adding and subtracting
deltas each time a enqueue or dequeue is increased or moved has proven to
be buggy and complicated, especially over long periods of time.
Recently a bug in counting free trbs was fixed, now taking into account
cancelled URBs that were turned into no-ops, preventing free_trbs to
slowly wander off causing unnecessary ring expansion. See
commit fe82f16aaf ("xhci: Fix incorrect tracking of free space on
transfer rings")
Turns out its a lot easier to just calculate the numer of free TRB
based on ring size and the current enqueue and dequeue pointer values.
This is currently only needed for the command ring as multi segment
transfer rings already ensures there is enough room the ring during
the ring expansion check.
We could get rid of the ring->num_trbs_free entry completely, but as
the xhci DbC code also uses it we don't clean that up in this patch.
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>
Message-ID: <20230602144009.1225632-8-mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The amount of new TRBs needed is calculated incorrectly when expanding a
transfer ring.
The room_on_ring() helper will correctly report that the ring needs
expansion if the enqueue pointer is about to reach the dequeue segment.
If enqueue reaches the dequeue segment then there is no easy way
to expand the ring by adding new segments between enqueue and dequeue.
This leads to ring expansion even if num_trbs_free is larger than
num_trbs we are queueing.
As a result we try to store a negative number in a unsigned int, leading
to a huge percieved trb need, and doubling of ring size.
Rework and rename the room_on_ring() to a helper that checks if ring
needs expansion, and return number of new segments needed. Don't rely on
the tracked ring->num_trbs_free value as turns out it has been unreliable.
Use ring enqueue and dequeue positions to determine expansion need.
The unsigned int issue was first reported first Chao zeng, and a bit
later seen in a real world bug.
Reported-by: chao zeng <chao.zengup@gmail.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>
Message-ID: <20230602144009.1225632-7-mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current function that both allocates and adds the interrupter isn't
optimal when using several interrupters. The array of interrupters need
to be protected with a lock while adding or removing interrupters.
If memory is allocated under the default xhci spinlock then GFP_KERNEL
can't be used.
There is no need to allocate the interrupter memory under the lock, so
split this code into separate unlocked allocate part, and a lock
protected add part.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Message-ID: <20230602144009.1225632-6-mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have a port structure for each port it makes sense to
move per port variables, timestamps and completions there.
Get rid of storing bitfileds and arrays of port specific items per bus.
Move
unsigned long resume_done;
insigned long rexit_ports
struct completion rexit_done;
struct completion u3exit_done;
Rename rexit_ports to rexit_active, and remove a redundant hcd
speed check while checking if rexit_active is set.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230202150505.618915-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xHC supports several interrupters, each with its own mmio register set,
event ring and MSI/MSI-X vector. Transfers can be assigned different
interrupters when queued. See xhci 4.17 for details.
Current driver only supports one interrupter.
Create a xhci_interrupter structure containing an event ring, pointer to
mmio registers for this interrupter, variables to store registers over s3
suspend, erst, etc. Add functions to create and free an interrupter, and
pass an interrupter pointer to functions that deal with events.
Secondary interrupters are also useful without having an interrupt vector.
One use case is the xHCI audio sideband offloading where a DSP can take
care of specific audio endpoints.
When all transfer events of an offloaded endpoint can be mapped to a
separate interrupter event ring the DSP can poll this ring, and we can mask
these events preventing waking up the CPU.
Only minor functional changes such as clearing some of the interrupter
registers when freeing the interrupter.
Still create only one primary interrupter.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230202150505.618915-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
