After _gadget_stop_activity is executed, we can consider the hardware
operation for gadget has finished, and the udc can be stopped and enter
low power mode. So, any later hardware operations (from usb_ep_ops APIs
or usb_gadget_ops APIs) should be considered invalid, any deinitializatons
has been covered at _gadget_stop_activity.
I meet this problem when I plug out usb cable from PC using mass_storage
gadget, my callstack like: vbus interrupt->.vbus_session->
composite_disconnect ->pm_runtime_put_sync(&_gadget->dev),
the composite_disconnect will call fsg_disable, but fsg_disable calls
usb_ep_disable using async way, there are register accesses for
usb_ep_disable. So sometimes, I get system hang due to visit register
without clock, sometimes not.
The Linux Kernel USB maintainer Alan Stern suggests this kinds of solution.
See: http://marc.info/?l=linux-usb&m=138541769810983&w=2.
Cc: <stable@vger.kernel.org> #v4.9+
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20190820020503.27080-2-peter.chen@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The variable retval is being initialized with a value that is never
read and it is being updated later with a new value. The
initialization is redundant and can be removed. Also remove a blank
line.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190704150341.759-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
An endpoint conflict occurs when the USB is working in device mode
during an isochronous communication. When the endpointA IN direction
is an isochronous IN endpoint, and the host sends an IN token to
endpointA on another device, then the OUT transaction may be missed
regardless the OUT endpoint number. Generally, this occurs when the
device is connected to the host through a hub and other devices are
connected to the same hub.
The affected OUT endpoint can be either control, bulk, isochronous, or
an interrupt endpoint. After the OUT endpoint is primed, if an IN token
to the same endpoint number on another device is received, then the OUT
endpoint may be unprimed (cannot be detected by software), which causes
this endpoint to no longer respond to the host OUT token, and thus, no
corresponding interrupt occurs.
There is no good workaround for this issue, the only thing the software
could do is numbering isochronous IN from the highest endpoint since we
have observed most of device number endpoint from the lowest.
Cc: <stable@vger.kernel.org> #v3.14+
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some hardware implementations require to configure pins differently
according to the USB role (host/device), this can be an update of the
pins routing or a simple GPIO value change.
This patch introduces new optional "host" and "device" pinctrls.
If these pinctrls are defined by the device, they are respectively
selected on host/device role start.
If a default pinctrl exist, it is restored on host/device role stop.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.
This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.
No copyright headers or other non-license-description text was removed.
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case the usb phy has the capability to detect usb charger type,
do it when vbus is on.
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
NVIDIA Tegra20 UDC can't cope with unaligned DMA and require a USB gadget
quirk that avoids SKB buffer alignment to be set in order to make Ethernet
Gadget working. Later Tegra generations do not require that quirk. Let's
add a new platform data flag that allows to enable USB gadget quirk for
platforms that require it.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Simplify return logic to avoid unnecessary variable assignment.
This issue was detected using Coccinelle and the following
semantic patch:
@@
local idexpression ret;
expression e;
@@
-ret =
+return
e;
-return ret;
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
- Add sysfs entry for role switch
- Update gadget state after gadget back from suspend
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJY9XecAAoJEEhZKYFQ1nG7PuQH+wR+qFiaswoJA3q+2sdqQDdD
vN1FLT93o3ObgnmYwbZZDxdGeB6e+AJ/K8tQCOVqm8AnaNOzDwCYJoBTa5nPaS5k
c+E4JlciG2NJG1s+eGVhZUPTQD3qS47vkgHymgtlTbQPDJDZy7k5nu7H1GSI7mvM
7AH4uavzMIqsZcQTAln6BvIr2FQHh996LnUHDvYSZ6Y+8cws9IPMbSIiao3s3SiZ
fULYJbVfDOd0LuxHOn7AdKrmlDJ/Gi2vmR4xQLlwvXEYk5/NUcSc1Yo5lVZcDUBR
MzX4bLvhLi4SNLXLJhfqYjXcPXddXxawL/TRGDmT0B/1N8CCtBWJkNpIgx9q6dk=
=opDd
-----END PGP SIGNATURE-----
Merge tag 'usb-ci-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-next
Peter writes:
Two changes for this v4.12-rc1:
- Add sysfs entry for role switch
- Update gadget state after gadget back from suspend
Sometimes, the user needs to adjust some properties for controllers, eg
the role for controller, we add sysfs group for them.
The attribute 'role' is used to switch host/gadget role dynamically, the
uewr can read the current role, and write the other role compare to
current one to finish the switch.
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Set the dma for chipidea from sysdev. This is inherited from its
parent node. Also, do not set dma mask for child as it is not required
now.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sriram Dash <sriram.dash@nxp.com>
Acked-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Gadget state is set to be suspended when bus suspened, but not updated
after resume, this patch saves the gadget state before suspend and
restores it after resume.
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
The CI_HDRC_CONTROLLER_STOPPED_EVENT may want to call sleeping
APIs similar to how _gadget_stop_activity() may. Let's drop the
lock across the event so that glue drivers can make sleeping
calls.
Cc: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
We don't call hw_device_reset() with the ci->lock held, so it
doesn't seem like this lock here is protecting anything. Let's
just remove it. This allows us to call sleeping functions like
phy_init() from within the CI_HDRC_CONTROLLER_RESET_EVENT hook.
Acked-by: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
- Properly mark little endian descriptors for udc
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJYO4X5AAoJEEhZKYFQ1nG78yYH/A8GJ6a3pBwvgF3XUhZusp75
w1yg7TnP4aPXDFdS2dpS0buFrBji/0MxTZm3aKNKIHL2jF6ZRW5TvhapA9xv7ezY
BhJOMXMUQAQSG/hnnu8QBJcrd0de3+EUhK6jYKInhvtNQUWl1jW073VAudlp2u4L
lVeHg49+u/10KlZ1Y6yipOH/KzfrOM1oGYBwyl7KMA48R2EASJ0FATcwUM/tRUX3
n6suCg/Z0VVFRdeYkiJdgnjxIbI+QR6TPMV+MWT1O32EniWm3pQT4G3WODooVqO9
oLc+4xgMoPkoiN5XwkYRNZ3wqhDp7xk2v10XJ7zTP1Xrqt2YFBk8K+Ls2/eQmGU=
=uOYb
-----END PGP SIGNATURE-----
Merge tag 'usb-ci-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-next
Peter writes:
- Adding ULPI PHY support for imx53
- Properly mark little endian descriptors for udc
The DMA descriptors are little endian, and we do a pretty good
job of handling them with the proper le32_to_cpu() markings, but
we don't actually mark them as __le32. This means checkers like
sparse can't easily find new bugs. Let's mark the members of
structures properly and fix the few places where we're missing
conversions.
Cc: Peter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Now that usb_endpoint_maxp() only returns the lowest
11 bits from wMaxPacketSize, we can remove the &
operation from this driver.
Cc: Peter Chen <Peter.Chen@nxp.com>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
We have introduced a helper to calculate multiplier
value from wMaxPacketSize. Start using it.
Acked-by: Peter Chen <Peter.Chen@nxp.com>
Cc: <linux-usb@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
According to Documentation/CodingStyle:
"The preferred form for passing a size of a struct is the following:
p = kmalloc(sizeof(*p), ...);
"
, so do as suggested to improve readability.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
No need to split the dma_pool_zalloc() line into two as it can
perfectly fit into a single line.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
We can make the code simpler by using dma_pool_zalloc() instead
of calling dma_pool_alloc() and then a memset().
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
This driver make assumptions about the value of the direction flags.
So better use them in comparisons to improve the readability.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
The endpoint fifo is already flushed in _ep_nuke so there
is no need to flush it twice.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Since there should be a write barrier before every call of
hw_ep_prime we could move it into hw_ep_prime.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Problems with the signal integrity of the high speed USB data lines or
noise on reference ground lines can cause the i.MX6 USB controller to
violate USB specs and exhibit unexpected behavior.
It was observed that USBi_UI interrupts were triggered first and when
isr_setup_status_phase was called, ci->status was NULL, which lead to a
NULL pointer dereference kernel panic.
This patch fixes the kernel panic, emits a warning once and returns
-EPIPE to halt the device and let the host get stalled.
It also adds a comment to point people, who are experiencing this issue,
to their USB hardware design.
Cc: <stable@vger.kernel.org> #4.1+
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
When the controller is configured to be dual role and it's in host mode,
if bind udc and gadgt driver, those gadget operations will do gadget
disconnect and finally pull down DP line, which will break host function.
Cc: <stable@vger.kernel.org> # 4.1+
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Since gadget driver will handle this request, so controller driver bypass
it.
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
retval is assigned to be -EOVERFLOW but is overwritten later before
it's used, remove this unused value assignment.
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Since we need to mount debugfs to show/store the things we
want to debug, it is duplicated to add another configuration
to enable it. Meanwhile, with CONFIG_USB_CHIPIDEA_DEBUG,
we can't support chipidea debugfs at runtime.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Cc: Jun Li <jun.li@freescale.com>
_hardware_enqueue() didn't check for errors when using
add_td_to_list() which can fail if dma_pool_alloc fails, thus
causing a kernel panic when lastnode->ptr is NULL.
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Update comments to reflect current state of functions.
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
replace dma_pool_alloc and memset with a single call to dma_pool_zalloc
Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch is to support load and unload gadget driver in full OTG mode.
Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Tested-by: Jiada Wang <jiada_wang@mentor.com>
Cc: <stable@vger.kernel.org> #v4.0+
According to spec, there are functional and protocol stalls.
For functional stall, it is for bulk and interrupt endpoints,
below are cases for it:
- Host sends SET_FEATURE request for Set-Halt, the udc driver
needs to set stall, and return true unconditionally.
- The gadget driver may call usb_ep_set_halt to stall certain
endpoints, if there is a transfer in pending, the udc driver
should not set stall, and return -EAGAIN accordingly.
These two kinds of stall need to be cleared by host using CLEAR_FEATURE
request (Clear-Halt).
For protocol stall, it is for control endpoint, this stall will
be set if the control request has failed. This stall will be
cleared by next setup request (hardware will do it).
It fixed usbtest (drivers/usb/misc/usbtest.c) Test 13 "set/clear halt"
test failure, meanwhile, this change has been verified by
USB2 CV Compliance Test and MSC Tests.
Cc: <stable@vger.kernel.org> #3.10+
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
The main changes are adding several system interfaces for
tuning performance, and each vendors can adjust them according
to their design configurations.
Others are tiny improvements, like more well siTD supports,
USB_DEVICE_A_HNP_SUPPORT supports, etc.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJVzU3lAAoJEEhZKYFQ1nG7nZ4H/AsCAhoiUqcyP4fRziaZzexa
F55CuhIVd6vg6vhuiccoUo4XZXR6IsZikczNowWphqXhtQUBr/rvv0VSb2sMxZfn
AgdNuinhGUat4rdcf0earr9+EQzjbdrHoxDzFKes21S0vS+J3TaYUk6F7Q6sUL81
t97itMmKBrffMZLsQzB9MJo4E8mD4JNlWu/ezGNu11ZD2/w8Ha7GpyExyb2AGHrs
M1rlE6Ph8AKpyECI7OecCxPIDyDRuUQ8Bvj+MkR9BrDX1gOv512ZLfRbIGJCqVOO
A2Urzh/jEI9e7ttGqSpMxGYKZ4wvZ7Ta5IvLLseb0vszM2oQGDNHcJx7fKOuUVU=
=IIud
-----END PGP SIGNATURE-----
Merge tag 'usb-ci-v4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-next
Peter writes:
USB: chipidea updates for v4.3-rc1
The main changes are adding several system interfaces for
tuning performance, and each vendors can adjust them according
to their design configurations.
Others are tiny improvements, like more well siTD supports,
USB_DEVICE_A_HNP_SUPPORT supports, etc.
The zero-length packet is the sendor tells the receiver that there
is no more data, so it is only needed at the TX side.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
We can support USB OTG 1.3 USB_DEVICE_A_HNP_SUPPORT request when
the driver supports OTG FSM mode.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Convert endpoint configuration to new capabilities model.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Since some chipidea based controller is not otg capable, add ci->is_otg
condition when setting is_otg flag for gadget.
Signed-off-by: Li Jun <jun.li@freescale.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Acked-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Init and update otg capabilities by DT, set gadget's otg capabilities
accordingly.
Acked-by: Peter Chen <peter.chen@freescale.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
By pass pullup DP in OTG fsm mode when do gadget connect, to let it handled
by OTG state machine.
This patch can fix the problem you found with my HNP polling patchset after
below 3 patches introduced:
467a78c usb: chipidea: udc: apply new usb_udc_vbus_handler interface
628ef0d usb: udc: add usb_udc_vbus_handler
dfea9c9 usb: udc: store usb_udc pointer in struct usb_gadget
Problem:
- Connect USB cable and MicroAB cable between two boards
- Boot up two boards
- load g_mass_storage at B-device side, the enumeration will success,
and A will see a usb mass-storage device
- load g_mass_storage at A-device side, the problem has occurred, the
connection will be lost at the beginning, then connect again.
This patch is based on
commit eff933c1d3a2e046492b3dfc86db813856553a29
(chipidea: pci: make it depends on NOP_USB_XCEIV)
on branch peter-usb-dev of
git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb.git
Signed-off-by: Li Jun <jun.li@freescale.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
As usual, a big pile of commits. This time a total
of 111 non-merge commits.
Other than the usual set of cleanups and non-critical
fixes, we have some interesting work for AM335x's MUSB
babble recovery. Now that takes a lot less time and we
don't have to Reset MUSB all the time.
The printer gadget has been converted to configfs interface
and the atmel udc has learned suspend/resume with wakeup.
Signed-off-by: Felipe Balbi <balbi@ti.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIcBAABAgAGBQJVEZlvAAoJEIaOsuA1yqREvPMP/1dxQ6ufjkfmBmeZWiDWmwQs
uoLskjNqVlnmcjWdasEwUSKMJMYfxNAmabYCx7ZWdmcDi0FNvmrjSfXqmM5uG5bF
UKgP/7KbiK9WSRAcAuFEqYCMcAoH2CcLhlZ7BF7Peo+WxeQrh0A4ZPxh4VVJI2D4
47/bpXFqPydVZyZurpfB0QA1r5jjsG+tJdP/LJKv6/g38XSBs4cgFUzzBWDN8212
YVKlCiRWRwnCOrYFP1pf/gR4SM8UF4Vd+lDZ28JnwcxCmTKKMhAAoHjgckV6UctW
Ur+hshsuvPwFWm9Rqp77TnO37LranaFUR2W2cBUGiPSZaUeXsdOhORpT+S64nuZi
ZEw4qp9QlRwH8wCBT0m/Uozv+CZ7VP41hjYdFpcUevd/XLPQjx1ddn032jGYsrtC
o+drLGtuULimusf/14zs1X4ejLdeYy6f0hLzqyDS8zTHAjToAmrM3Uw9nQWxWauB
rHdTYMrgMGoolnIFVSLgR6xbGMu9wCYexylKFwVWEV6xrj4ZgpoVitUGg5DphCQy
FdEepkeWgAUTcYC3wcIUHHC9wVS3YgPWRmyKjnh65kIFDGjPjHMK1eW06RGuhld/
A92UJNIga34RtUXSUrcuwRBtWY+pDE/6XxppqzxTKAMjT9HV8JNPZGHu+2nKP0kp
qu9PqszUGOyCuTG9+A+E
=U+M2
-----END PGP SIGNATURE-----
Merge tag 'usb-for-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next
Felipe writes:
usb: patches for v4.1 merge window
As usual, a big pile of commits. This time a total
of 111 non-merge commits.
Other than the usual set of cleanups and non-critical
fixes, we have some interesting work for AM335x's MUSB
babble recovery. Now that takes a lot less time and we
don't have to Reset MUSB all the time.
The printer gadget has been converted to configfs interface
and the atmel udc has learned suspend/resume with wakeup.
Signed-off-by: Felipe Balbi <balbi@ti.com>
It can move all pullup/pulldown operation control to udc-core
through usb_gadget_connect/usb_gadget_disconnect according to
vbus status.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
At chipidea revision 2.40a, there is a below errata:
9000531823 B2-Medium Adding a dTD to a Primed Endpoint May Not Get Recognized
Title: Adding a dTD to a Primed Endpoint May Not Get Recognized
Impacted Configuration: All device mode configurations.
Description:
There is an issue with the add dTD tripwire semaphore (ATDTW bit in USBCMD register)
that can cause the controller to ignore a dTD that is added to a primed endpoint.
When this happens, the software can read the tripwire bit and the status bit at '1'
even though the endpoint is unprimed.
After executing a dTD, the device controller endpoint state machine executes a final
read of the dTD terminate bit to check if the application added a dTD to the linked
list at the last moment. This read is done in the finpkt_read_latest_next_td (44) state.
After the read is performed, if the terminate bit is still set, the state machine moves
to unprime the endpoint. The decision to unprime the endpoint is done in the
checkqh_decision (59) state, based on the value of the terminate bit.
Before reaching the checkqh_decision state, the state machine traverses the
writeqhtd_status (57), writeqh_status (56), and release_prime_mask (42) states.
As shown in the waveform, the ep_addtd_tripwire_clr signal is not set to clear
the tripwire bit in these states.
Workaround:
The software must implement a periodic poll cycle, and check for each dTD
pending on execution (Active = 1), if the enpoint is primed. It can do this by reading
the corresponding bits in the ENDPTPRIME and ENDPTSTAT registers. If these bits are
read at 0, the software needs to re-prime the endpoint by writing 1 to the corresponding
bit in the ENDPTPRIME register. This can be done for every microframe, every frame or
with a larger interval, depending on the urgency of transfer execution for the application.
Tested-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Greg Kroah-Hartman