FAILED: patch "[PATCH] staging: axis-fifo: Remove hardware resets for user errors" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

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 c6e8d85fafa7193613db37da29c0e8d6e2515b13
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025051251-pardon-stellar-d13f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From c6e8d85fafa7193613db37da29c0e8d6e2515b13 Mon Sep 17 00:00:00 2001
From: Gabriel Shahrouzi <gshahrouzi@gmail.com>
Date: Fri, 18 Apr 2025 20:43:06 -0400
Subject: [PATCH] staging: axis-fifo: Remove hardware resets for user errors

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 <gshahrouzi@gmail.com>
Link: https://lore.kernel.org/r/20250419004306.669605-1-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 04b3dc3cfe7c..351f983ef914 100644
--- a/drivers/staging/axis-fifo/axis-fifo.c
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -393,16 +393,14 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
 
 	bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET);
 	if (!bytes_available) {
-		dev_err(fifo->dt_device, "received a packet of length 0 - fifo core will be reset\n");
-		reset_ip_core(fifo);
+		dev_err(fifo->dt_device, "received a packet of length 0\n");
 		ret = -EIO;
 		goto end_unlock;
 	}
 
 	if (bytes_available > len) {
-		dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu) - fifo core will be reset\n",
+		dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu)\n",
 			bytes_available, len);
-		reset_ip_core(fifo);
 		ret = -EINVAL;
 		goto end_unlock;
 	}
@@ -411,8 +409,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
 		/* this probably can't happen unless IP
 		 * registers were previously mishandled
 		 */
-		dev_err(fifo->dt_device, "received a packet that isn't word-aligned - fifo core will be reset\n");
-		reset_ip_core(fifo);
+		dev_err(fifo->dt_device, "received a packet that isn't word-aligned\n");
 		ret = -EIO;
 		goto end_unlock;
 	}
@@ -433,7 +430,6 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
 
 		if (copy_to_user(buf + copied * sizeof(u32), tmp_buf,
 				 copy * sizeof(u32))) {
-			reset_ip_core(fifo);
 			ret = -EFAULT;
 			goto end_unlock;
 		}
@@ -542,7 +538,6 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
 
 		if (copy_from_user(tmp_buf, buf + copied * sizeof(u32),
 				   copy * sizeof(u32))) {
-			reset_ip_core(fifo);
 			ret = -EFAULT;
 			goto end_unlock;
 		}