From 74c0b4c0ddf751578ce04e85075afbf7d6ef4229 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 4 Sep 2024 21:17:07 -0700 Subject: [PATCH] Input: libps2 - use guard notation when temporarily pausing serio ports Using guard notation makes the code more compact and error handling more robust by ensuring that serio ports are resumed in all code paths when control leaves critical section. Link: https://lore.kernel.org/r/20240905041732.2034348-3-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov --- drivers/input/serio/libps2.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c index 6d78a1fe00c1..c22ea532276e 100644 --- a/drivers/input/serio/libps2.c +++ b/drivers/input/serio/libps2.c @@ -108,13 +108,11 @@ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout) { int retval; - serio_pause_rx(ps2dev->serio); + guard(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); @@ -162,10 +160,10 @@ void ps2_drain(struct ps2dev *ps2dev, size_t maxbytes, unsigned int timeout) ps2_begin_command(ps2dev); - serio_pause_rx(ps2dev->serio); - ps2dev->flags = PS2_FLAG_CMD; - ps2dev->cmdcnt = maxbytes; - serio_continue_rx(ps2dev->serio); + scoped_guard(serio_pause_rx, ps2dev->serio) { + ps2dev->flags = PS2_FLAG_CMD; + ps2dev->cmdcnt = maxbytes; + } wait_event_timeout(ps2dev->wait, !(ps2dev->flags & PS2_FLAG_CMD), @@ -224,9 +222,9 @@ static int ps2_adjust_timeout(struct ps2dev *ps2dev, * use alternative probe to detect it. */ if (ps2dev->cmdbuf[1] == 0xaa) { - serio_pause_rx(ps2dev->serio); - ps2dev->flags = 0; - serio_continue_rx(ps2dev->serio); + scoped_guard(serio_pause_rx, ps2dev->serio) + ps2dev->flags = 0; + timeout = 0; } @@ -235,9 +233,9 @@ static int ps2_adjust_timeout(struct ps2dev *ps2dev, * won't be 2nd byte of ID response. */ if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) { - serio_pause_rx(ps2dev->serio); - ps2dev->flags = ps2dev->cmdcnt = 0; - serio_continue_rx(ps2dev->serio); + scoped_guard(serio_pause_rx, ps2dev->serio) + ps2dev->flags = ps2dev->cmdcnt = 0; + timeout = 0; } break; @@ -283,6 +281,10 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) memcpy(send_param, param, send); + /* + * Not using guard notation because we need to break critical + * section below while waiting for the response. + */ serio_pause_rx(ps2dev->serio); ps2dev->cmdcnt = receive; -- 2.25.1