The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 2ca34b508774aaa590fc3698a54204706ecca4ba # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025051209-visible-hassle-6995@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2ca34b508774aaa590fc3698a54204706ecca4ba Mon Sep 17 00:00:00 2001 From: Gabriel Shahrouzi gshahrouzi@gmail.com Date: Fri, 18 Apr 2025 21:29:37 -0400 Subject: [PATCH] staging: axis-fifo: Correct handling of tx_fifo_depth for size validation

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 gshahrouzi@gmail.com Link: https://lore.kernel.org/r/20250419012937.674924-1-gshahrouzi@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c index 7540c20090c7..04b3dc3cfe7c 100644 --- a/drivers/staging/axis-fifo/axis-fifo.c +++ b/drivers/staging/axis-fifo/axis-fifo.c @@ -775,9 +775,6 @@ static int axis_fifo_parse_dt(struct axis_fifo *fifo) goto end; }

- /* IP sets TDFV to fifo depth - 4 so we will do the same */ - fifo->tx_fifo_depth -= 4; - ret = get_dts_property(fifo, "xlnx,use-rx-data", &fifo->has_rx_fifo); if (ret) { dev_err(fifo->dt_device, "missing xlnx,use-rx-data property\n");