diff options
Diffstat (limited to 'drivers/input')
-rw-r--r-- | drivers/input/serio/libps2.c | 103 |
1 files changed, 71 insertions, 32 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c index 82befae..f05c407 100644 --- a/drivers/input/serio/libps2.c +++ b/drivers/input/serio/libps2.c @@ -26,35 +26,63 @@ MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>"); MODULE_DESCRIPTION("PS/2 driver library"); MODULE_LICENSE("GPL"); -static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout) +static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, + unsigned int timeout, unsigned int max_attempts) + __releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock) { + int attempt = 0; int error; - serio_pause_rx(ps2dev->serio); - ps2dev->nak = 1; - ps2dev->flags |= PS2_FLAG_ACK; - serio_continue_rx(ps2dev->serio); + lockdep_assert_held(&ps2dev->serio->lock); - 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)); + do { + ps2dev->nak = 1; + ps2dev->flags |= PS2_FLAG_ACK; + + serio_continue_rx(ps2dev->serio); + + 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)); + + serio_pause_rx(ps2dev->serio); + } while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts); - serio_pause_rx(ps2dev->serio); ps2dev->flags &= ~PS2_FLAG_ACK; - serio_continue_rx(ps2dev->serio); - return -ps2dev->nak; + if (!error) { + switch (ps2dev->nak) { + case 0: + break; + case PS2_RET_NAK: + error = -EAGAIN; + break; + case PS2_RET_ERR: + error = -EPROTO; + break; + default: + error = -EIO; + break; + } + } + + if (error || attempt > 1) + dev_dbg(&ps2dev->serio->dev, + "%02x - %d (%x), attempt %d\n", + byte, error, ps2dev->nak, attempt); + + return error; } /* * 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. + * It doesn't handle retransmission, the caller is expected to handle + * it when needed. * * ps2_sendbyte() can only be called from a process context. */ @@ -63,9 +91,13 @@ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout) { int retval; - retval = ps2_do_sendbyte(ps2dev, byte, timeout); + serio_pause_rx(ps2dev->serio); + + retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1); dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak); + serio_continue_rx(ps2dev->serio); + return retval; } EXPORT_SYMBOL(ps2_sendbyte); @@ -200,48 +232,48 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) unsigned int timeout; unsigned int send = (command >> 12) & 0xf; unsigned int receive = (command >> 8) & 0xf; - int rc = -1; + int rc; int i; u8 send_param[16]; if (receive > sizeof(ps2dev->cmdbuf)) { WARN_ON(1); - return -1; + return -EINVAL; } if (send && !param) { WARN_ON(1); - return -1; + return -EINVAL; } memcpy(send_param, param, send); serio_pause_rx(ps2dev->serio); + ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0; ps2dev->cmdcnt = receive; if (receive && param) for (i = 0; i < receive; i++) ps2dev->cmdbuf[(receive - 1) - i] = param[i]; - serio_continue_rx(ps2dev->serio); /* * Some devices (Synaptics) peform the reset before * ACKing the reset command, and so it can take a long * time before the ACK arrives. */ - if (ps2_do_sendbyte(ps2dev, command & 0xff, - command == PS2_CMD_RESET_BAT ? 1000 : 200)) { - serio_pause_rx(ps2dev->serio); + rc = ps2_do_sendbyte(ps2dev, command & 0xff, + command == PS2_CMD_RESET_BAT ? 1000 : 200, 2); + if (rc) goto out_reset_flags; - } for (i = 0; i < send; i++) { - if (ps2_do_sendbyte(ps2dev, param[i], 200)) { - serio_pause_rx(ps2dev->serio); + rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2); + if (rc) goto out_reset_flags; - } } + serio_continue_rx(ps2dev->serio); + /* * The reset command takes a long time to execute. */ @@ -263,8 +295,11 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) for (i = 0; i < receive; i++) param[i] = ps2dev->cmdbuf[(receive - 1) - i]; - if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) + if (ps2dev->cmdcnt && + (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) { + rc = -EPROTO; goto out_reset_flags; + } rc = 0; @@ -278,7 +313,11 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) ps2dev->nak, ps2dev->flags, receive, param ?: send_param); - return rc; + /* + * ps_command() handles resends itself, so do not leak -EAGAIN + * to the callers. + */ + return rc != -EAGAIN ? rc : -EPROTO; } EXPORT_SYMBOL(__ps2_command); |