add ioctl USBTMC_IOCTL_MSG_IN_ATTR that returns the specific
bmTransferAttributes field of the last DEV_DEP_MSG_IN Bulk-IN
header. This header is received by the read() function. The
meaning of the (u8) bitmap bmTransferAttributes is:
Bit 0 = EOM flag is set when the last transfer of a USBTMC
message is received.
Bit 1 = is set when the last byte is a termchar (e.g. '\n').
Note that this bit is always zero when the device does not support
the termchar feature or when termchar detection is not enabled
(see ioctl USBTMC_IOCTL_CONFIG_TERMCHAR).
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Wait until an SRQ (service request) is received on the interrupt pipe
or until the given period of time is expired. In contrast to the
poll() function this ioctl does not return when other (a)synchronous
I/O operations fail with EPOLLERR.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Submitted urbs are not allowed when system is suspended.
Thus the submitted urb waiting at interrupt pipe is killed
during suspend callback and submitted again when system resumes.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ioctl USBTMC_IOCTL_CLEANUP_IO kills all submitted urbs to OUT
and IN bulk, and clears all received data from IN bulk. Internal
transfer counters and error states are reset.
An application should use this ioctl after an asnychronous transfer
was canceled and/or error handling has finished.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioctl USBTMC_IOCTL_CANCEL_IO stops and kills all flying urbs of
last USBTMC_IOCTL_READ and USBTMC_IOCTL_WRITE function calls.
A subsequent call to USBTMC_IOCTL_READ or
USBTMC_IOCTL_WRITE_RESULT returns -ECANCELED with
information about current transferred data.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USBTMC_IOCTL_READ call provides for generic synchronous and
asynchronous reads on bulk IN to implement vendor specific library
routines.
Depending on transfer_size the function submits one or more urbs (up
to 16) each with a size of up to 4kB.
The flag USBTMC_FLAG_IGNORE_TRAILER can be used when the transmission
size is already known. Then the function does not truncate the
transfer_size to a multiple of 4 kB, but does reserve extra space
to receive the final short or zero length packet. Note that the
instrument is allowed to send up to wMaxPacketSize - 1 bytes at the
end of a message to avoid sending a zero length packet.
With flag USBTMC_FLAG_ASYNC the ioctl is non blocking. When no
received data is available, the read function submits as many urbs as
needed to receive transfer_size bytes. However the number of flying
urbs (=4kB) is limited to 16 even with subsequent calls of this ioctl.
Returns -EAGAIN when non blocking and no data is received.
Signals EPOLLIN | EPOLLRDNORM when asynchronous urbs are ready to
be read.
In non blocking mode the usbtmc_message.message pointer may be NULL
and the ioctl just submits urbs to initiate receiving data. However if
data is already available due to a previous non blocking call the ioctl
will return -EINVAL when the message pointer is NULL.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ioctl USBTMC_IOCTL_WRITE_RESULT copies current out_transfer_size
to given __u32 pointer and returns current out_status of the last
(asnynchronous) USBTMC_IOCTL_WRITE call.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The new ioctl USBTMC_IOCTL_WRITE sends a generic message to bulk OUT.
This ioctl is used for vendor specific or asynchronous I/O as well.
The message is split into chunks of 4k (page size).
Message size is aligned to 32 bit boundaries.
With flag USBTMC_FLAG_ASYNC the ioctl is non blocking.
With flag USBTMC_FLAG_APPEND additional urbs are queued and
out_status/out_transfer_size is not reset. EPOLLOUT | EPOLLWRNORM
is signaled when all submitted urbs are completed.
Flush flying urbs when file handle is closed or device is
suspended or reset.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add USBTMC_IOCTL_CTRL_REQUEST to send arbitrary requests on the
control pipe. Used by specific applications of IVI Foundation,
Inc. to implement VISA API functions: viUsbControlIn/Out.
The maximum length of control request is set to 4k.
This ioctl does not support compatibility for 32 bit
applications running on 64 bit systems. However all other
convenient ioctls of the USBTMC driver can still be used in 32
bit applications as well. Note that 32 bit applications running
on 32 bit target systems are not affected by this limitation.
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 6e22e3af7b.
The bug the patch describes to, has been already fixed in commit
2df6948428 ("USB: cdc-wdm: don't enable interrupts in USB-giveback")
so need to this, revert it.
Fixes: 6e22e3af7b ("usb: cdc-wdm: Fix a sleep-in-atomic-context bug in service_outstanding_interrupt()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit a81cf9799a.
The patch causes a regression, which I cannot find the reason for.
So let's revert for now, as a revert hurts only performance.
Original report:
I was trying to resolve the problem with Oliver but we don't get any conclusion
for 5 months, so I am now sending this to mail list and cdc_acm authors.
I am using simple request-response protocol to obtain the boiller parameters
in constant intervals.
A simple one transaction is:
1. opening the /dev/ttyACM0
2. sending the following 10-bytes request to the device:
unsigned char req[] = {0x02, 0xfe, 0x01, 0x05, 0x08, 0x02, 0x01, 0x69, 0xab, 0x03};
3. reading response (frame of 74 bytes length).
4. closing the descriptor
I am doing this transaction with 5 seconds intervals.
Before the bad commit everything was working correctly: I've got a requests and
a responses in a timely manner.
After the bad commit more time I am using the kernel module, more problems I have.
The graph [2] is showing the problem.
As you can see after module load all seems fine but after about 30 minutes I've got
a plenty of EAGAINs when doing read()'s and trying to read back the data.
When I rmmod and insmod the cdc_acm module again, then the situation is starting
over again: running ok shortly after load, and more time it is running, more EAGAINs
I have when calling read().
As a bonus I can see the problem on the device itself:
The device is configured as you can see here on this screen [3].
It has two transmision LEDs: TX and RX. Blink duration is set for 100ms.
This is a recording before the bad commit when all is working fine: [4]
And this is with the bad commit: [5]
As you can see the TX led is blinking wrongly long (indicating transmission?)
and I have problems doing read() calls (EAGAIN).
Reported-by: Mariusz Bialonczyk <manio@skyboo.net>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Fixes: a81cf9799a ("cdc-acm: implement put_char() and flush_chars()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
wdm_in_callback() is a completion handler function for the USB driver.
So it should not sleep. But it calls service_outstanding_interrupt(),
which calls usb_submit_urb() with GFP_KERNEL.
To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC.
This bug is found by my static analysis tool DSAC.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
add USBTMC_IOCTL_CONFIG_TERMCHAR to control TermChar handling
for next read(). Controls field 'TermChar' and Bit 1 of field
'bmTransferAttributes' of REQUEST_DEV_DEP_MSG_IN BULK-OUT header.
Allows enabling/disabling of terminating a read on reception of
term_char individually for each read request.
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
add USBTMC_IOCTL_EOM_ENABLE to specify EOM bit for next write()
call. Sets Bit 0 of field 'bmTransferAttributes' of DEV_DEP_MSG_OUT
Bulk-OUT Header.
Allows fine grained control over end of message handling on a
per file descriptor basis.
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
add USBTMC488_IOCTL_TRIGGER to send TRIGGER Bulk-OUT header
according to Subclass USB488 Specification
The usbtmc trigger command is equivalent to the IEEE 488 GET (Group
Execute Trigger) action. While the "*TRG" command can be sent as
data to perform the same operation, in some situations an instrument
will be busy and unable to process the data immediately in which
case the USBTMC488_IOCTL_TRIGGER can be used to trigger the
instrument with lower latency.
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add ioctls USBTMC_IOCTL_GET_TIMEOUT / USBTMC_IOCTL_SET_TIMEOUT to
get/set I/O timeout for specific file handle.
Different operations on an instrument can take different lengths of
time thus it is important to be able to set the timeout slightly
longer than the expected duration of each operation to optimise the
responsiveness of the application. As the instrument may be shared by
multiple applications the timeout should be settable on a per file
descriptor basis.
Tested-by: Dave Penkler <dpenkler@gmail.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add 'struct usbtmc_file_data' for each file handle to cache last
srq_byte (=Status Byte with SRQ) received by usbtmc_interrupt(..)
usbtmc488_ioctl_read_stb returns cached srq_byte when available for
each file handle to avoid race conditions of concurrent applications.
SRQ now sets EPOLLPRI instead of EPOLLIN since EPOLLIN is now reserved
for asynchronous reads
Tested-by: Dave Penkler <dpenkler@gmail.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.
Cc: Oliver Neukum <oneukum@suse.com>
Cc: "Bjørn Mork" <bjorn@mork.no>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the code path
__usb_hcd_giveback_urb()
-> wdm_in_callback()
-> service_outstanding_interrupt()
The function service_outstanding_interrupt() will unconditionally enable
interrupts during unlock and invoke usb_submit_urb() with GFP_KERNEL.
If the HCD completes in BH (like ehci does) then the context remains
atomic due local_bh_disable() and enabling interrupts does not change
this.
Defer the error case handling to a workqueue as suggested by Oliver
Neukum. In case of an error the worker performs the read out and wakes
the user.
Fixes: c1da59dad0 ("cdc-wdm: Clear read pipeline in case of error")
Cc: Robert Foss <robert.foss@collabora.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Guido Kiener
Sebastian Andrzej Siewior
Oliver Neukum
Jia-Ju Bai
Greg Kroah-Hartman
Lubomir Rintel