From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: linux-input@vger.kernel.org
Cc: Erick Archer <erick.archer@outlook.com>,
Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
linux-kernel@vger.kernel.org
Subject: [PATCH 3/6] Input: iforce - use guard notation when acquiring mutex and spinlock
Date: Tue, 3 Sep 2024 21:31:00 -0700 [thread overview]
Message-ID: <20240904043104.1030257-4-dmitry.torokhov@gmail.com> (raw)
In-Reply-To: <20240904043104.1030257-1-dmitry.torokhov@gmail.com>
Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/input/joystick/iforce/iforce-ff.c | 48 +++++++---------
.../input/joystick/iforce/iforce-packets.c | 57 ++++++++-----------
drivers/input/joystick/iforce/iforce-serio.c | 36 +++++-------
drivers/input/joystick/iforce/iforce-usb.c | 13 ++---
4 files changed, 68 insertions(+), 86 deletions(-)
diff --git a/drivers/input/joystick/iforce/iforce-ff.c b/drivers/input/joystick/iforce/iforce-ff.c
index 95c0348843e6..8c78cbe553c8 100644
--- a/drivers/input/joystick/iforce/iforce-ff.c
+++ b/drivers/input/joystick/iforce/iforce-ff.c
@@ -21,14 +21,13 @@ static int make_magnitude_modifier(struct iforce* iforce,
unsigned char data[3];
if (!no_alloc) {
- mutex_lock(&iforce->mem_mutex);
- if (allocate_resource(&(iforce->device_memory), mod_chunk, 2,
- iforce->device_memory.start, iforce->device_memory.end, 2L,
- NULL, NULL)) {
- mutex_unlock(&iforce->mem_mutex);
+ guard(mutex)(&iforce->mem_mutex);
+
+ if (allocate_resource(&iforce->device_memory, mod_chunk, 2,
+ iforce->device_memory.start,
+ iforce->device_memory.end,
+ 2L, NULL, NULL))
return -ENOSPC;
- }
- mutex_unlock(&iforce->mem_mutex);
}
data[0] = LO(mod_chunk->start);
@@ -54,14 +53,13 @@ static int make_period_modifier(struct iforce* iforce,
period = TIME_SCALE(period);
if (!no_alloc) {
- mutex_lock(&iforce->mem_mutex);
- if (allocate_resource(&(iforce->device_memory), mod_chunk, 0x0c,
- iforce->device_memory.start, iforce->device_memory.end, 2L,
- NULL, NULL)) {
- mutex_unlock(&iforce->mem_mutex);
+ guard(mutex)(&iforce->mem_mutex);
+
+ if (allocate_resource(&iforce->device_memory, mod_chunk, 0x0c,
+ iforce->device_memory.start,
+ iforce->device_memory.end,
+ 2L, NULL, NULL))
return -ENOSPC;
- }
- mutex_unlock(&iforce->mem_mutex);
}
data[0] = LO(mod_chunk->start);
@@ -94,14 +92,13 @@ static int make_envelope_modifier(struct iforce* iforce,
fade_duration = TIME_SCALE(fade_duration);
if (!no_alloc) {
- mutex_lock(&iforce->mem_mutex);
+ guard(mutex)(&iforce->mem_mutex);
+
if (allocate_resource(&(iforce->device_memory), mod_chunk, 0x0e,
- iforce->device_memory.start, iforce->device_memory.end, 2L,
- NULL, NULL)) {
- mutex_unlock(&iforce->mem_mutex);
+ iforce->device_memory.start,
+ iforce->device_memory.end,
+ 2L, NULL, NULL))
return -ENOSPC;
- }
- mutex_unlock(&iforce->mem_mutex);
}
data[0] = LO(mod_chunk->start);
@@ -131,14 +128,13 @@ static int make_condition_modifier(struct iforce* iforce,
unsigned char data[10];
if (!no_alloc) {
- mutex_lock(&iforce->mem_mutex);
+ guard(mutex)(&iforce->mem_mutex);
+
if (allocate_resource(&(iforce->device_memory), mod_chunk, 8,
- iforce->device_memory.start, iforce->device_memory.end, 2L,
- NULL, NULL)) {
- mutex_unlock(&iforce->mem_mutex);
+ iforce->device_memory.start,
+ iforce->device_memory.end,
+ 2L, NULL, NULL))
return -ENOSPC;
- }
- mutex_unlock(&iforce->mem_mutex);
}
data[0] = LO(mod_chunk->start);
diff --git a/drivers/input/joystick/iforce/iforce-packets.c b/drivers/input/joystick/iforce/iforce-packets.c
index 763642c8cee9..8c2531e2977c 100644
--- a/drivers/input/joystick/iforce/iforce-packets.c
+++ b/drivers/input/joystick/iforce/iforce-packets.c
@@ -31,49 +31,42 @@ int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data)
int c;
int empty;
int head, tail;
- unsigned long flags;
/*
* Update head and tail of xmit buffer
*/
- spin_lock_irqsave(&iforce->xmit_lock, flags);
-
- head = iforce->xmit.head;
- tail = iforce->xmit.tail;
-
-
- if (CIRC_SPACE(head, tail, XMIT_SIZE) < n+2) {
- dev_warn(&iforce->dev->dev,
- "not enough space in xmit buffer to send new packet\n");
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
- return -1;
- }
+ scoped_guard(spinlock_irqsave, &iforce->xmit_lock) {
+ head = iforce->xmit.head;
+ tail = iforce->xmit.tail;
+
+ if (CIRC_SPACE(head, tail, XMIT_SIZE) < n + 2) {
+ dev_warn(&iforce->dev->dev,
+ "not enough space in xmit buffer to send new packet\n");
+ return -1;
+ }
- empty = head == tail;
- XMIT_INC(iforce->xmit.head, n+2);
+ empty = head == tail;
+ XMIT_INC(iforce->xmit.head, n + 2);
/*
* Store packet in xmit buffer
*/
- iforce->xmit.buf[head] = HI(cmd);
- XMIT_INC(head, 1);
- iforce->xmit.buf[head] = LO(cmd);
- XMIT_INC(head, 1);
-
- c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
- if (n < c) c=n;
-
- memcpy(&iforce->xmit.buf[head],
- data,
- c);
- if (n != c) {
- memcpy(&iforce->xmit.buf[0],
- data + c,
- n - c);
+ iforce->xmit.buf[head] = HI(cmd);
+ XMIT_INC(head, 1);
+ iforce->xmit.buf[head] = LO(cmd);
+ XMIT_INC(head, 1);
+
+ c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE);
+ if (n < c)
+ c = n;
+
+ memcpy(&iforce->xmit.buf[head], data, c);
+ if (n != c)
+ memcpy(&iforce->xmit.buf[0], data + c, n - c);
+
+ XMIT_INC(head, n);
}
- XMIT_INC(head, n);
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
/*
* If necessary, start the transmission
*/
diff --git a/drivers/input/joystick/iforce/iforce-serio.c b/drivers/input/joystick/iforce/iforce-serio.c
index 2380546d7978..75b85c46dfa4 100644
--- a/drivers/input/joystick/iforce/iforce-serio.c
+++ b/drivers/input/joystick/iforce/iforce-serio.c
@@ -28,45 +28,39 @@ static void iforce_serio_xmit(struct iforce *iforce)
iforce);
unsigned char cs;
int i;
- unsigned long flags;
if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
return;
}
- spin_lock_irqsave(&iforce->xmit_lock, flags);
+ guard(spinlock_irqsave)(&iforce->xmit_lock);
-again:
- if (iforce->xmit.head == iforce->xmit.tail) {
- iforce_clear_xmit_and_wake(iforce);
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
- return;
- }
+ do {
+ if (iforce->xmit.head == iforce->xmit.tail)
+ break;
- cs = 0x2b;
+ cs = 0x2b;
- serio_write(iforce_serio->serio, 0x2b);
+ serio_write(iforce_serio->serio, 0x2b);
- serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]);
- cs ^= iforce->xmit.buf[iforce->xmit.tail];
- XMIT_INC(iforce->xmit.tail, 1);
-
- for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
serio_write(iforce_serio->serio,
iforce->xmit.buf[iforce->xmit.tail]);
cs ^= iforce->xmit.buf[iforce->xmit.tail];
XMIT_INC(iforce->xmit.tail, 1);
- }
- serio_write(iforce_serio->serio, cs);
+ for (i = iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
+ serio_write(iforce_serio->serio,
+ iforce->xmit.buf[iforce->xmit.tail]);
+ cs ^= iforce->xmit.buf[iforce->xmit.tail];
+ XMIT_INC(iforce->xmit.tail, 1);
+ }
- if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
- goto again;
+ serio_write(iforce_serio->serio, cs);
- iforce_clear_xmit_and_wake(iforce);
+ } while (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags));
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
+ iforce_clear_xmit_and_wake(iforce);
}
static int iforce_serio_get_id(struct iforce *iforce, u8 id,
diff --git a/drivers/input/joystick/iforce/iforce-usb.c b/drivers/input/joystick/iforce/iforce-usb.c
index cba92bd590a8..1f00f76b0174 100644
--- a/drivers/input/joystick/iforce/iforce-usb.c
+++ b/drivers/input/joystick/iforce/iforce-usb.c
@@ -25,13 +25,11 @@ static void __iforce_usb_xmit(struct iforce *iforce)
struct iforce_usb *iforce_usb = container_of(iforce, struct iforce_usb,
iforce);
int n, c;
- unsigned long flags;
- spin_lock_irqsave(&iforce->xmit_lock, flags);
+ guard(spinlock_irqsave)(&iforce->xmit_lock);
if (iforce->xmit.head == iforce->xmit.tail) {
iforce_clear_xmit_and_wake(iforce);
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
return;
}
@@ -45,7 +43,8 @@ static void __iforce_usb_xmit(struct iforce *iforce)
/* Copy rest of data then */
c = CIRC_CNT_TO_END(iforce->xmit.head, iforce->xmit.tail, XMIT_SIZE);
- if (n < c) c=n;
+ if (n < c)
+ c = n;
memcpy(iforce_usb->out->transfer_buffer + 1,
&iforce->xmit.buf[iforce->xmit.tail],
@@ -53,11 +52,12 @@ static void __iforce_usb_xmit(struct iforce *iforce)
if (n != c) {
memcpy(iforce_usb->out->transfer_buffer + 1 + c,
&iforce->xmit.buf[0],
- n-c);
+ n - c);
}
XMIT_INC(iforce->xmit.tail, n);
- if ( (n=usb_submit_urb(iforce_usb->out, GFP_ATOMIC)) ) {
+ n=usb_submit_urb(iforce_usb->out, GFP_ATOMIC);
+ if (n) {
dev_warn(&iforce_usb->intf->dev,
"usb_submit_urb failed %d\n", n);
iforce_clear_xmit_and_wake(iforce);
@@ -66,7 +66,6 @@ static void __iforce_usb_xmit(struct iforce *iforce)
/* The IFORCE_XMIT_RUNNING bit is not cleared here. That's intended.
* As long as the urb completion handler is not called, the transmiting
* is considered to be running */
- spin_unlock_irqrestore(&iforce->xmit_lock, flags);
}
static void iforce_usb_xmit(struct iforce *iforce)
--
2.46.0.469.g59c65b2a67-goog
next prev parent reply other threads:[~2024-09-04 4:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-04 4:30 [PATCH 0/6] Convert joystick drivers to use new cleanup facilities Dmitry Torokhov
2024-09-04 4:30 ` [PATCH 1/6] Input: db9 - use guard notation when acquiring mutex Dmitry Torokhov
2024-11-20 18:33 ` David Lechner
2024-11-21 3:52 ` Dmitry Torokhov
2024-09-04 4:30 ` [PATCH 2/6] Input: gamecon " Dmitry Torokhov
2024-09-04 4:31 ` Dmitry Torokhov [this message]
2024-09-04 4:31 ` [PATCH 4/6] Input: n64joy " Dmitry Torokhov
2024-09-04 4:31 ` [PATCH 5/6] Input: turbografx " Dmitry Torokhov
2024-09-04 4:31 ` [PATCH 6/6] Input: xpad - use guard notation when acquiring mutex and spinlock Dmitry Torokhov
2024-09-04 4:43 ` [PATCH 0/6] Convert joystick drivers to use new cleanup facilities Dmitry Torokhov
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