From 54999c0d94b3c26625f896f8e3460bc029821578 Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti@mev.co.uk>
Date: Tue, 23 Feb 2021 14:30:47 +0000
Subject: [PATCH] staging: comedi: dmm32at: Fix endian problem for AI command data
Git-commit: 54999c0d94b3c26625f896f8e3460bc029821578
Patch-mainline: v5.12-rc3
References: git-fixes

The analog input subdevice supports Comedi asynchronous commands that
use Comedi's 16-bit sample format.  However, the call to
`comedi_buf_write_samples()` is passing the address of a 32-bit integer
variable.  On bigendian machines, this will copy 2 bytes from the wrong
end of the 32-bit value.  Fix it by changing the type of the variable
holding the sample value to `unsigned short`.

[note: the bug was introduced in commit 1700529b24cc ("staging: comedi:
Dmm32at: use comedi_buf_write_samples()") but the patch applies better
to the later (but in the same kernel release) commit 0c0eadadcbe6e
("staging: comedi: dmm32at: introduce dmm32_ai_get_sample()").]

Fixes: 0c0eadadcbe6e ("staging: comedi: dmm32at: introduce dmm32_ai_get_sample()")
Cc: <stable@vger.kernel.org> # 3.19+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-7-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/comedi/drivers/dmm32at.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/dmm32at.c b/drivers/staging/comedi/drivers/dmm32at.c
index 17e6018918bb..56682f01242f 100644
--- a/drivers/staging/comedi/drivers/dmm32at.c
+++ b/drivers/staging/comedi/drivers/dmm32at.c
@@ -404,7 +404,7 @@ static irqreturn_t dmm32at_isr(int irq, void *d)
 {
 	struct comedi_device *dev = d;
 	unsigned char intstat;
-	unsigned int val;
+	unsigned short val;
 	int i;
 
 	if (!dev->attached) {
-- 
2.26.2