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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2018-01-02 12:21:49 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2018-02-02 16:50:25 -0800
commit147b903da65daedc90dbeb66a75dd608a6a41ef2 (patch)
tree99fac314945fbc3c61ed86f305b73990f2a90c06 /drivers/input/serio
parent08be954b7a7de6742d3d47e4dc20e3b086410761 (diff)
downloadlinux-147b903da65daedc90dbeb66a75dd608a6a41ef2.tar.bz2
Input: libps2 - add debugging statements
Debugging via i8042.debug and analyzing raw PS/2 data stream may be cumbersome as you need to locate the boundaries of commands, decipher the sliced commands, etc, etc. Let's add a bit more high level debug statements for ps2_sendbyte(), ps2_command(), and ps2_sliced_command(). We do not introduce a new module parameter, but rater rely on the kernel having dynamic debug facility enabled (which most everyone has nowadays). Enable with: echo "file libps2.c +pf" > /sys/kernel/debug/dynamic_debug/control or add "libps2.dyndbg=+pf" to the kernel command line. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input/serio')
-rw-r--r--drivers/input/serio/libps2.c52
1 files changed, 39 insertions, 13 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index e96ae477f0b5..82befae4dab0 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -26,22 +26,20 @@ MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
MODULE_DESCRIPTION("PS/2 driver library");
MODULE_LICENSE("GPL");
-/*
- * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
- * It doesn't handle retransmission, though it could - because if there
- * is a need for retransmissions device has to be replaced anyway.
- *
- * ps2_sendbyte() can only be called from a process context.
- */
-
-int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
+static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
{
+ int error;
+
serio_pause_rx(ps2dev->serio);
ps2dev->nak = 1;
ps2dev->flags |= PS2_FLAG_ACK;
serio_continue_rx(ps2dev->serio);
- if (serio_write(ps2dev->serio, byte) == 0)
+ error = serio_write(ps2dev->serio, byte);
+ if (error)
+ dev_dbg(&ps2dev->serio->dev,
+ "failed to write %#02x: %d\n", byte, error);
+ else
wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_ACK),
msecs_to_jiffies(timeout));
@@ -52,6 +50,24 @@ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
return -ps2dev->nak;
}
+
+/*
+ * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
+ * It doesn't handle retransmission, though it could - because if there
+ * is a need for retransmissions device has to be replaced anyway.
+ *
+ * ps2_sendbyte() can only be called from a process context.
+ */
+
+int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
+{
+ int retval;
+
+ retval = ps2_do_sendbyte(ps2dev, byte, timeout);
+ dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak);
+
+ return retval;
+}
EXPORT_SYMBOL(ps2_sendbyte);
void ps2_begin_command(struct ps2dev *ps2dev)
@@ -186,6 +202,7 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
unsigned int receive = (command >> 8) & 0xf;
int rc = -1;
int i;
+ u8 send_param[16];
if (receive > sizeof(ps2dev->cmdbuf)) {
WARN_ON(1);
@@ -197,6 +214,8 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
return -1;
}
+ memcpy(send_param, param, send);
+
serio_pause_rx(ps2dev->serio);
ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
ps2dev->cmdcnt = receive;
@@ -210,14 +229,14 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
* ACKing the reset command, and so it can take a long
* time before the ACK arrives.
*/
- if (ps2_sendbyte(ps2dev, command & 0xff,
- command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
+ if (ps2_do_sendbyte(ps2dev, command & 0xff,
+ command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
serio_pause_rx(ps2dev->serio);
goto out_reset_flags;
}
for (i = 0; i < send; i++) {
- if (ps2_sendbyte(ps2dev, param[i], 200)) {
+ if (ps2_do_sendbyte(ps2dev, param[i], 200)) {
serio_pause_rx(ps2dev->serio);
goto out_reset_flags;
}
@@ -253,6 +272,12 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);
+ dev_dbg(&ps2dev->serio->dev,
+ "%02x [%*ph] - %x/%08lx [%*ph]\n",
+ command & 0xff, send, send_param,
+ ps2dev->nak, ps2dev->flags,
+ receive, param ?: send_param);
+
return rc;
}
EXPORT_SYMBOL(__ps2_command);
@@ -296,6 +321,7 @@ int ps2_sliced_command(struct ps2dev *ps2dev, u8 command)
}
out:
+ dev_dbg(&ps2dev->serio->dev, "%02x - %d\n", command, retval);
ps2_end_command(ps2dev);
return retval;
}