kernel/linux.git/drivers/staging/axis-fifo, branch v6.1.168

staging: axis-fifo: flush RX FIFO on read errors

2025-10-15T09:56:24+00:00

commit 82a051e2553b9e297cba82a975d9c538b882c79e upstream. Flush stale data from the RX FIFO in case of errors, to avoid reading old data when new packets arrive. Commit c6e8d85fafa7 ("staging: axis-fifo: Remove hardware resets for user errors") removed full FIFO resets from the read error paths, which fixed potential TX data losses, but introduced this RX issue. Fixes: c6e8d85fafa7 ("staging: axis-fifo: Remove hardware resets for user errors") Cc: stable@vger.kernel.org Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250912101322.1282507-2-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: fix TX handling on copy_from_user() failure

2025-10-15T09:56:24+00:00

commit 6d07bee10e4bdd043ec7152cbbb9deb27033c9e2 upstream. 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 c6e8d85fafa7 ("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: c6e8d85fafa7 ("staging: axis-fifo: Remove hardware resets for user errors") Cc: stable@vger.kernel.org Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250912101322.1282507-1-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: fix maximum TX packet length check

2025-10-15T09:56:24+00:00

commit 52ff2b840bc723f3be1f096f8017c78e0515858c upstream. Since commit 2ca34b508774 ("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: 2ca34b508774 ("staging: axis-fifo: Correct handling of tx_fifo_depth for size validation") Cc: stable@vger.kernel.org Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250817171350.872105-1-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: Correct handling of tx_fifo_depth for size validation

2025-05-18T06:21:22+00:00

commit 2ca34b508774aaa590fc3698a54204706ecca4ba upstream. 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: 4a965c5f89de ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core") Cc: stable@vger.kernel.org Signed-off-by: Gabriel Shahrouzi Link: https://lore.kernel.org/r/20250419012937.674924-1-gshahrouzi@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: Remove hardware resets for user errors

2025-05-18T06:21:22+00:00

commit c6e8d85fafa7193613db37da29c0e8d6e2515b13 upstream. 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: 4a965c5f89de ("staging: add driver for Xilinx AXI-Stream FIFO v4.1 IP core") Cc: stable@vger.kernel.org Signed-off-by: Gabriel Shahrouzi Link: https://lore.kernel.org/r/20250419004306.669605-1-gshahrouzi@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: initialize timeouts in init only

2023-05-24T16:32:40+00:00

[ Upstream commit 752cbd8f191678e86aa754f795546b7f06b7f171 ] 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 Suggested-by: Greg Kroah-Hartman Signed-off-by: Khadija Kamran Link: https://lore.kernel.org/r/ZBN3XAsItCiTk7CV@khadija-virtual-machine Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

staging: axis-fifo: Use platform_get_irq() to get the interrupt

2021-12-30T10:54:56+00:00

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 Link: https://lore.kernel.org/r/20211224161334.31123-4-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: convert to use miscdevice

2021-09-13T06:49:53+00:00

Using a struct class, a cdev, and another device just for a single minor device is total overkill. Just use a dynamic misc device instead, saving lots of logic and memory. Cc: Jacob Feder Cc: Lee Jones Cc: Muhammad Usama Anjum Link: https://lore.kernel.org/r/YTdPvBgKW6cKYrvb@kroah.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: axis-fifo: Fix function naming in the documentation

2021-05-10T09:19:27+00:00

Fixes the following W=1 kernel build warning(s): drivers/staging/axis-fifo/axis-fifo.c:356: warning: expecting prototype for axis_fifo_write(). Prototype was for axis_fifo_read() instead Cc: Greg Kroah-Hartman Cc: Jacob Feder Cc: linux-staging@lists.linux.dev Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20210414181129.1628598-52-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: axis-fifo: Fix some formatting issues

2021-05-10T09:19:26+00:00

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 Cc: "John B. Wyatt IV" Cc: Jacob Feder Cc: linux-staging@lists.linux.dev Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20210414181129.1628598-37-lee.jones@linaro.org Signed-off-by: Greg Kroah-Hartman