The USB_GPIB_SET_LINES command string used to be: "\nIBDC \n" but when
we were merging this code into the upstream kernel we deleted the space
character before the newline to make checkpatch happy. That turned
out to be a mistake.
The "\nIBDC" part of the string is a command that we pass to the
firmware and the next character is a variable u8 value.
It gets set in set_control_line().
msg[leng - 2] = value ? (retval & ~line) : retval | line;
where leng is the length of the command string.
Imagine the parameter was supposed to be "8".
With the pre-merge code the command string would be "\nIBDC8\n"
With the post-merge code the command string became "\nIBD8\n"
The firmware doesn't recognize "IBD8" as a valid command and rejects it.
Putting a "." where the parameter is supposed to go fixes the driver
and makes checkpatch happy. Same thing with the other define and
the in-line assignment.
Reported-by: Marcello Carla' <marcello.carla@xxxxxxx>
Fixes: fce79512a96a ("staging: gpib: Add LPVO DIY USB GPIB driver")
Co-developed-by: Marcello Carla' <marcello.carla@xxxxxxx>
Signed-off-by: Marcello Carla' <marcello.carla@xxxxxxx>
Signed-off-by: Dave Penkler <dpenkler@xxxxxxxxx>
---
v1 -> v2
Add more details to the commit message
Add Signed-off by co developer
Add spaces around assignment
Fix tabs
v2 -> v3
Adopt and adapt the more explanatory commit message kindly
provided by Dan Carpenter
drivers/staging/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c b/drivers/staging/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
index 1a8eb3bfb61c..81c110f29e76 100644
--- a/drivers/staging/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
+++ b/drivers/staging/gpib/lpvo_usb_gpib/lpvo_usb_gpib.c
@@ -97,8 +97,8 @@ module_param(debug, int, 0644);
#define USB_GPIB_DEBUG_ON "\nIBDE\xAA\n"
#define USB_GPIB_SET_LISTEN "\nIBDT0\n"
#define USB_GPIB_SET_TALK "\nIBDT1\n"
-#define USB_GPIB_SET_LINES "\nIBDC\n"
-#define USB_GPIB_SET_DATA "\nIBDM\n"
+#define USB_GPIB_SET_LINES "\nIBDC.\n"
+#define USB_GPIB_SET_DATA "\nIBDM.\n"
#define USB_GPIB_READ_LINES "\nIBD?C\n"
#define USB_GPIB_READ_DATA "\nIBD?M\n"
#define USB_GPIB_READ_BUS "\nIBD??\n"
@@ -587,7 +587,7 @@ static int usb_gpib_command(gpib_board_t *board,
size_t *bytes_written)
{
int i, retval;
- char command[6] = "IBc\n";
+ char command[6] = "IBc.\n";
DIA_LOG(1, "enter %p\n", board);
--
2.47.1
