Remove the check for zero-length packets as this condition cannot
occur during normal operation. According to the Xilinx AXI4-Stream
FIFO Product Guide (PG080), in the Receive Length Register (RLR)
description: "The smallest packet that can be received is 1 byte."
A zero-length packet would indicate a bug in the IP core itself.
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://patch.msgid.link/20251227212640.3321310-6-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Module parameters for timeouts are a poor interface choice as they
affect all device instances globally rather than being configurable
per file descriptor.
The current implementation also returns -EAGAIN on timeout, requiring
userspace to implement retry loops around blocking operations.
Remove the read_timeout and write_timeout module parameters. The next
commit adds poll() support, allowing applications to implement timeout
handling using standard poll()/select() interfaces.
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://patch.msgid.link/20251227212640.3321310-1-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The irq handler iterates through the interrupt bits one by one in a while()
loop, clearing one bit at a time. This is unnecessary and inefficient, as
the 'Interrupt Status Register' can be cleared with a single write
operation.
Also the irq handler checks for some interrupts that are masked out in the
'Interrupt Enable Register', so they are never triggered.
Simplify the irq handler by removing the checks for interrupts that are
masked out and clear the whole 'Interrupt Status Register' in one go. The
macros that are no longer relevant are also removed.
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://lore.kernel.org/r/20250919195400.3180039-2-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull staging driver fixes from Greg KH:
"Here are some staging driver fixes that missed 6.17-final due to my
travel schedule. They fix a number of reported issues in the axis-fifo
driver, one of which was just independently discovered by someone else
today so someone is looking at this code.
All of these fixes have been in linux-next for many weeks with no
reported issues"
* tag 'staging-6.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: axis-fifo: flush RX FIFO on read errors
staging: axis-fifo: fix TX handling on copy_from_user() failure
staging: axis-fifo: fix maximum TX packet length check
If copy_from_user() fails, write() currently returns -EFAULT, but any
partially written data leaves the TX FIFO in an inconsistent state.
Subsequent write() calls then fail with "transmit length mismatch"
errors.
Once partial data is written to the hardware FIFO, it cannot be removed
without a TX reset. Commit c6e8d85faf ("staging: axis-fifo: Remove
hardware resets for user errors") removed a full FIFO reset for this case,
which fixed a potential RX data loss, but introduced this TX issue.
Fix this by introducing a bounce buffer: copy the full packet from
userspace first, and write to the hardware FIFO only if the copy
was successful.
Fixes: c6e8d85faf ("staging: axis-fifo: Remove hardware resets for user errors")
Cc: stable@vger.kernel.org
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://lore.kernel.org/r/20250912101322.1282507-1-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 2ca34b5087 ("staging: axis-fifo: Correct handling of
tx_fifo_depth for size validation"), write() operations with packets
larger than 'tx_fifo_depth - 4' words are no longer rejected with -EINVAL.
Fortunately, the packets are not actually getting transmitted to hardware,
otherwise they would be raising a 'Transmit Packet Overrun Error'
interrupt, which requires a reset of the TX circuit to recover from.
Instead, the request times out inside wait_event_interruptible_timeout()
and always returns -EAGAIN, since the wake up condition can never be true
for these packets. But still, they unnecessarily block other tasks from
writing to the FIFO and the EAGAIN return code signals userspace to retry
the write() call, even though it will always fail and time out.
According to the AXI4-Stream FIFO reference manual (PG080), the maximum
valid packet length is 'tx_fifo_depth - 4' words, so attempting to send
larger packets is invalid and should not be happening in the first place:
> The maximum packet that can be transmitted is limited by the size of
> the FIFO, which is (C_TX_FIFO_DEPTH–4)*(data interface width/8) bytes.
Therefore, bring back the old behavior and outright reject packets larger
than 'tx_fifo_depth - 4' with -EINVAL. Add a comment to explain why the
check is necessary. The dev_err() message was removed to avoid cluttering
the dmesg log if an invalid packet is received from userspace.
Fixes: 2ca34b5087 ("staging: axis-fifo: Correct handling of tx_fifo_depth for size validation")
Cc: stable@vger.kernel.org
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://lore.kernel.org/r/20250817171350.872105-1-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Axis-fifo devices use physical addresses in their name, for example
'axis_fifo_0x43c00000'. This is generally frowned upon and it does not
follow the usual naming scheme that uses unique identifiers.
Therefore, use ida_alloc()/ida_free() to implement unique identifiers
for axis-fifo device names (i.e. axis_fifo0, axis_fifo1, etc.).
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://lore.kernel.org/r/20250811085417.2641674-2-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unhandled fault: imprecise external abort (0x1406) at 0xaec8d000
[aec8d000] *pgd=03f74831, *pte=0525c75f, *ppte=0525cc7f
Internal error: Oops - BUG: 1406 [#1] SMP ARM
Hardware name: Xilinx Zynq Platform
PC is at sysfs_read+0xc4/0xd8
LR is at dev_attr_show+0x6c/0xc0
pc : [<c0ff9298>] lr : [<c0adad38>] psr: 60070013
sp : e09abd18 ip : c3193000 fp : c0adaccc
r10: 00000000 r9 : c3192000 r8 : 183abab5
r7 : c1d5d5a8 r6 : c2d71440 r5 : 00000024 r4 : c3192000
r3 : e0a60024 r2 : 00000000 r1 : c3192000 r0 : c2d71444
...
Call trace:
sysfs_read from dev_attr_show+0x6c/0xc0
dev_attr_show from sysfs_kf_seq_show+0x270/0x360
sysfs_kf_seq_show from seq_read_iter+0x7f4/0x10bc
seq_read_iter from vfs_read+0x350/0x3d0
vfs_read from ksys_read+0x104/0x194
ksys_read from ret_fast_syscall+0x0/0x54
The same abort is triggered if a read is attempted on RDFD register when
the fifo is empty.
Therefore, remove the sysfs interface and only let read()/write() modify
the fifo registers. For debugging purposes, a simple read-only debugfs
interface is added in the next patch.
Fixes: 4a965c5f89 ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core")
Signed-off-by: Ovidiu Panait <ovidiu.panait.oss@gmail.com>
Link: https://lore.kernel.org/r/20250720183833.3570345-1-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The axis-fifo driver performs a full hardware reset (via
reset_ip_core()) in several error paths within the read and write
functions. This reset flushes both TX and RX FIFOs and resets the
AXI-Stream links.
Allow the user to handle the error without causing hardware disruption
or data loss in other FIFO paths.
Fixes: 4a965c5f89 ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core")
Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
Link: https://lore.kernel.org/r/20250419004306.669605-1-gshahrouzi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove erroneous subtraction of 4 from the total FIFO depth read from
device tree. The stored depth is for checking against total capacity,
not initial vacancy. This prevented writes near the FIFO's full size.
The check performed just before data transfer, which uses live reads of
the TDFV register to determine current vacancy, correctly handles the
initial Depth - 4 hardware state and subsequent FIFO fullness.
Fixes: 4a965c5f89 ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core")
Cc: stable@vger.kernel.org
Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com>
Link: https://lore.kernel.org/r/20250419012937.674924-1-gshahrouzi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.
Convert all staging drivers to use .remove(), with the eventual goal to
drop struct platform_driver::remove_new(). As .remove() and .remove_new()
have the same prototypes, conversion is done by just changing the structure
member name in the driver initializer.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20241001085751.282113-1-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra-video
Acked-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
Acked-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20230714175002.4064428-1-robh@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230403154014.2564054-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Initialize the module parameters, read_timeout and write_timeout once in
init().
Module parameters can only be set once and cannot be modified later, so we
don't need to evaluate them again when passing the parameters to
wait_event_interruptible_timeout().
Convert datatype of {read,write}_timeout from 'int' to 'long int' because
implicit conversion of 'long int' to 'int' in statement
'{read,write}_timeout = MAX_SCHEDULE_TIMEOUT' results in an overflow.
Change format specifier for {read,write}_timeout from %i to %li.
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
Link: https://lore.kernel.org/r/ZBN3XAsItCiTk7CV@khadija-virtual-machine
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.
In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20211224161334.31123-4-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes the following W=1 kernel build warning(s):
drivers/staging/axis-fifo/axis-fifo.c:356: warning: Function parameter or member 'f' not described in 'axis_fifo_read'
drivers/staging/axis-fifo/axis-fifo.c:356: warning: Function parameter or member 'buf' not described in 'axis_fifo_read'
drivers/staging/axis-fifo/axis-fifo.c:356: warning: Function parameter or member 'len' not described in 'axis_fifo_read'
drivers/staging/axis-fifo/axis-fifo.c:356: warning: Function parameter or member 'off' not described in 'axis_fifo_read'
drivers/staging/axis-fifo/axis-fifo.c:356: warning: expecting prototype for axis_fifo_write(). Prototype was for axis_fifo_read() instead
drivers/staging/axis-fifo/axis-fifo.c:478: warning: Function parameter or member 'f' not described in 'axis_fifo_write'
drivers/staging/axis-fifo/axis-fifo.c:478: warning: Function parameter or member 'buf' not described in 'axis_fifo_write'
drivers/staging/axis-fifo/axis-fifo.c:478: warning: Function parameter or member 'len' not described in 'axis_fifo_write'
drivers/staging/axis-fifo/axis-fifo.c:478: warning: Function parameter or member 'off' not described in 'axis_fifo_write'
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "John B. Wyatt IV" <jbwyatt4@gmail.com>
Cc: Jacob Feder <jacobsfeder@gmail.com>
Cc: linux-staging@lists.linux.dev
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210414181129.1628598-37-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Following the device's documentation guidance, reading a packet from the
device or writing a packet to it must be atomic. Previously, only
reading device's vacancy (before writing on it) or occupancy (before
reading from it) was locked. Hence, effectively reading the packet or
writing the packet wasn't locked at all. However, reading a packet (and
writing one, to a lesser extent) requires to read 3 different registers
in a specific order, without missing one or else we should reset the
device.
This patch fixes the device's locking mechanism on the FIFO character
device. As the device was using copy_from_user() and copy_to_user(), we
need to replace spinlocks with mutexes.
Signed-off-by: Quentin Deslandes <quentin.deslandes@itdev.co.uk>
Link: https://lore.kernel.org/r/20200121103958.12941-1-quentin.deslandes@itdev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently CONFIG_XIL_AXIS_FIFO=y implicitly depends on
CONFIG_HAS_IOMEM=y; consequently, on architectures without IOMEM we get
the following build error:
ld: drivers/staging/axis-fifo/axis-fifo.o: in function `axis_fifo_probe':
drivers/staging/axis-fifo/axis-fifo.c:809: undefined reference to `devm_ioremap_resource'
Fix the build error by adding the unspecified dependency.
Reported-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Link: https://lore.kernel.org/r/20191211192742.95699-7-brendanhiggins@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some properties were parsed from the device tree and then ignored by the
driver. Some would return an error if absent from the device tree, then
return an error if they were found because they are unsupported by the
driver.
Avoid parsing unused properties and clearly explain in the documentation
the ignored / unsupported properties.
Signed-off-by: Quentin Deslandes <quentin.deslandes@itdev.co.uk>
Link: https://lore.kernel.org/r/20191101214232.16960-2-quentin.deslandes@itdev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.
Also since commit f467c5640c ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:
...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:
config FOO
bool
config FOO
bool
default n
With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few remaining drivers/staging/*/Makefile files that do not
have SPDX identifiers in them. Add the correct GPL-2.0 identifier to
them to make scanning tools happy.
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few remaining drivers/staging/*/Kconfig files that do not
have SPDX identifiers in them. Add the correct GPL-2.0 identifier to
them to make scanning tools happy.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When building without CONFIG_OF, the compiler loses track of the flow
control in axis_fifo_probe(), and thinks that many variables are used
without an initialization even though we actually leave the function
before the first use:
drivers/staging/axis-fifo/axis-fifo.c: In function 'axis_fifo_probe':
drivers/staging/axis-fifo/axis-fifo.c:900:5: error: 'rxd_tdata_width' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (rxd_tdata_width != 32) {
^
drivers/staging/axis-fifo/axis-fifo.c:907:5: error: 'txd_tdata_width' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (txd_tdata_width != 32) {
^
drivers/staging/axis-fifo/axis-fifo.c:914:5: error: 'has_tdest' may be used uninitialized in this function [-Werror=maybe-uninitialized]
if (has_tdest) {
^
drivers/staging/axis-fifo/axis-fifo.c:919:5: error: 'has_tid' may be used uninitialized in this function [-Werror=maybe-uninitialized]
When CONFIG_OF is set, this does not happen, and since the driver cannot
work without it, just add that option as a Kconfig dependency.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
