From 147b903da65daedc90dbeb66a75dd608a6a41ef2 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Tue, 2 Jan 2018 12:21:49 -0800 Subject: 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 --- drivers/input/serio/libps2.c | 52 +++++++++++++++++++++++++++++++++----------- 1 file changed, 39 insertions(+), 13 deletions(-) (limited to 'drivers/input') 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 "); 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; } -- cgit v1.2.3-59-g8ed1b