MIRRORS/linux-yocto
1
0
Fork 0
mirror of git://git.yoctoproject.org/linux-yocto.git synced 2025-10-22 23:13:01 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

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

Browse Source 
commit 82a051e2553b9e297cba82a975d9c538b882c79e upstream.

Flush stale data from the RX FIFO in case of errors, to avoid reading
old data when new packets arrive.

Commit c6e8d85faf ("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: 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/20250912101322.1282507-2-ovidiu.panait.oss@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ovidiu Panait 2025-09-12 13:13:22 +03:00 committed by Greg Kroah-Hartman
parent a3c71d6c83
commit e857421992
1 changed files with 11 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/staging/axis-fifo/axis-fifo.c
View File

@ -396,6 +396,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
}
bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET);
words_available = bytes_available / sizeof(u32);
if (!bytes_available) {
dev_err(fifo->dt_device, "received a packet of length 0\n");
ret = -EIO;
@ -406,7 +407,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
dev_err(fifo->dt_device, "user read buffer too small (available bytes=%zu user buffer bytes=%zu)\n",
bytes_available, len);
ret = -EINVAL;
goto end_unlock;
goto err_flush_rx;
}
if (bytes_available % sizeof(u32)) {
@ -415,11 +416,9 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
*/
dev_err(fifo->dt_device, "received a packet that isn't word-aligned\n");
ret = -EIO;
goto end_unlock;
goto err_flush_rx;
}
words_available = bytes_available / sizeof(u32);
/* read data into an intermediate buffer, copying the contents
* to userspace when the buffer is full
*/
@ -431,18 +430,23 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
tmp_buf[i] = ioread32(fifo->base_addr +
XLLF_RDFD_OFFSET);
}
words_available -= copy;
if (copy_to_user(buf + copied * sizeof(u32), tmp_buf,
copy * sizeof(u32))) {
ret = -EFAULT;
goto end_unlock;
goto err_flush_rx;
}
copied += copy;
words_available -= copy;
}
mutex_unlock(&fifo->read_lock);
ret = bytes_available;
return bytes_available;
err_flush_rx:
while (words_available--)
ioread32(fifo->base_addr + XLLF_RDFD_OFFSET);
end_unlock:
mutex_unlock(&fifo->read_lock);