kernel/linux.git/drivers/staging/axis-fifo, branch v6.19.11

staging: axis-fifo: drop debug print of remapped base address

2025-10-13T07:09:29+00:00

The probe function prints the remapped base address with dev_dbg(). This message is not useful and printing kernel addresses is discouraged, so remove the debug print. Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250919195400.3180039-6-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: drop redundant read/write_flags from axis_fifo

2025-10-13T07:09:29+00:00

The driver stores file flags (read_flags/write_flags) in the axis_fifo struct, duplicating information already available in struct file. Switch to using f->f_flags directly in read/write paths and open(), removing the unnecessary fields. Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250919195400.3180039-5-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: remove get_dts_property() helper

2025-10-13T07:09:29+00:00

The get_dts_property() wrapper around of_property_read_u32() adds no real value and duplicates error handling. Inline the calls directly in axis_fifo_parse_dt() to reduce indirection and simplify the code. Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250919195400.3180039-4-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: remove unneeded irq field from struct axis_fifo

2025-10-13T07:09:29+00:00

The irq number returned by platform_get_irq() is stored in struct axis_fifo during probe but it is never used afterwards. Drop the redundant irq field and use a local variable instead. Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250919195400.3180039-3-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: simplify interrupt handling

2025-10-13T07:09:28+00:00

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 Link: https://lore.kernel.org/r/20250919195400.3180039-2-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

staging: axis-fifo: add compatible strings for v4.2 and v4.3

2025-10-13T07:09:28+00:00

The driver is compatible with both v4.2 and v4.3 versions of the Xilinx AXI4-Stream FIFO, so add compatible strings for them. Signed-off-by: Ovidiu Panait Link: https://lore.kernel.org/r/20250919195400.3180039-1-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'staging-6.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2025-10-07T18:41:06+00:00

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

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

2025-09-12T14:21:46+00:00

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

2025-09-12T14:21:46+00:00

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

2025-08-18T14:27:59+00:00

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