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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: kernel@pengutronix.de, linux-pwm@vger.kernel.org
Subject: [PATCH v4 001/115] pwm: Reduce number of pointer dereferences in pwm_device_request()
Date: Wed,  6 Dec 2023 12:43:15 +0100	[thread overview]
Message-ID: <e0b5c32bca45e90d47f26f917574ccdce422b5dc.1701860672.git.u.kleine-koenig@pengutronix.de> (raw)
In-Reply-To: <cover.1701860672.git.u.kleine-koenig@pengutronix.de>

pwm->chip and pwm->chip->ops are used several times in this function.
Introduce local variables for these.

There is no semantical change, but with ARCH=arm, allmodconfig and
gcc-13 bloat-o-meter reports a slight improvement:

	add/remove: 1/1 grow/shrink: 1/1 up/down: 8/-36 (-28)
	Function                                     old     new   delta
	pwm_apply_state                              476     480      +4
	__initcall__kmod_core__307_1092_pwm_debugfs_init4       -       4      +4
	__initcall__kmod_core__307_1090_pwm_debugfs_init4       4       -      -4
	pwm_request_from_chip                        628     596     -32
	Total: Before=15091, After=15063, chg -0.19%

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Note this patch was already sent individually, find it at
https://lore.kernel.org/linux-pwm/20231130072105.966848-1-u.kleine-koenig@pengutronix.de

 drivers/pwm/core.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index f60b715abe62..eea93ed8a49b 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -59,22 +59,24 @@ static struct pwm_chip *pwmchip_find_by_name(const char *name)
 static int pwm_device_request(struct pwm_device *pwm, const char *label)
 {
 	int err;
+	struct pwm_chip *chip = pwm->chip;
+	const struct pwm_ops *ops = chip->ops;
 
 	if (test_bit(PWMF_REQUESTED, &pwm->flags))
 		return -EBUSY;
 
-	if (!try_module_get(pwm->chip->owner))
+	if (!try_module_get(chip->owner))
 		return -ENODEV;
 
-	if (pwm->chip->ops->request) {
-		err = pwm->chip->ops->request(pwm->chip, pwm);
+	if (ops->request) {
+		err = ops->request(chip, pwm);
 		if (err) {
-			module_put(pwm->chip->owner);
+			module_put(chip->owner);
 			return err;
 		}
 	}
 
-	if (pwm->chip->ops->get_state) {
+	if (ops->get_state) {
 		/*
 		 * Zero-initialize state because most drivers are unaware of
 		 * .usage_power. The other members of state are supposed to be
@@ -84,7 +86,7 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
 		 */
 		struct pwm_state state = { 0, };
 
-		err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
+		err = ops->get_state(chip, pwm, &state);
 		trace_pwm_get(pwm, &state, err);
 
 		if (!err)
-- 
2.42.0


  reply	other threads:[~2023-12-06 11:48 UTC|newest]

Thread overview: 127+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-06 11:43 [PATCH v4 000/115] pwm: Fix lifetime issues for pwm_chips Uwe Kleine-König
2023-12-06 11:43 ` Uwe Kleine-König [this message]
2023-12-06 11:43 ` [PATCH v4 002/115] pwm: crc: Use consistent variable naming for driver data Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 006/115] pwm: cros-ec: Change prototype of helpers to prepare further changes Uwe Kleine-König
2023-12-07  2:06   ` Tzung-Bi Shih
2023-12-06 11:43 ` [PATCH v4 007/115] pwm: Provide a macro to get the parent device of a given chip Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 008/115] pwm: ab8500: Make use of pwmchip_parent() macro Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 009/115] pwm: atmel: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 010/115] pwm: atmel-tcb: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 011/115] pwm: bcm-kona: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 012/115] pwm: crc: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 013/115] pwm: cros-ec: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 014/115] pwm: dwc: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 015/115] pwm: ep93xx: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 016/115] pwm: fsl-ftm: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 017/115] pwm: img: Make use of parent device pointer in driver data Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 018/115] pwm: imx27: Make use of pwmchip_parent() macro Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 019/115] pwm: jz4740: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 020/115] pwm: lpc18xx-sct: Make use of parent device pointer in driver data Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 021/115] pwm: lpss: Make use of pwmchip_parent() macro Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 022/115] pwm: mediatek: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 023/115] pwm: meson: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 024/115] pwm: mtk-disp: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 025/115] pwm: omap: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 026/115] pwm: pca9685: Store parent device in driver data Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 027/115] pwm: raspberrypi-poe: Make use of pwmchip_parent() macro Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 028/115] pwm: rcar: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 029/115] pwm: rz-mtu3: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 030/115] pwm: samsung: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 031/115] pwm: sifive: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 032/115] pwm: stm32-lp: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 033/115] pwm: stm32: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 034/115] pwm: stmpe: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 035/115] pwm: sun4i: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 036/115] pwm: tiecap: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 037/115] pwm: tiehrpwm: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 038/115] pwm: twl-led: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 039/115] pwm: twl: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 040/115] pwm: vt8500: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 041/115] staging: greybus: pwm: " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 042/115] pwm: Provide wrappers for storing and getting driver private data Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 043/115] pwm: Provide devm_pwmchip_alloc() function Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 044/115] pwm: ab8500: Make use of " Uwe Kleine-König
2023-12-06 11:43 ` [PATCH v4 045/115] pwm: apple: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 046/115] pwm: atmel-hlcdc: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 047/115] pwm: atmel: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 048/115] pwm: atmel-tcb: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 049/115] pwm: bcm2835: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 050/115] pwm: bcm-iproc: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 051/115] pwm: bcm-kona: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 052/115] pwm: berlin: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 053/115] pwm: brcmstb: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 054/115] pwm: clk: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 055/115] pwm: clps711x: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 056/115] pwm: crc: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 057/115] pwm: cros-ec: " Uwe Kleine-König
2023-12-07  2:07   ` Tzung-Bi Shih
2023-12-06 11:44 ` [PATCH v4 058/115] pwm: dwc: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 059/115] pwm: ep93xx: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 060/115] pwm: fsl-ftm: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 061/115] pwm: hibvt: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 062/115] pwm: img: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 063/115] pwm: imx1: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 064/115] pwm: imx27: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 065/115] pwm: imx-tpm: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 066/115] pwm: intel-lgm: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 067/115] pwm: iqs620a: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 068/115] pwm: jz4740: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 069/115] pwm: keembay: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 070/115] pwm: lp3943: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 071/115] pwm: lpc18xx-sct: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 072/115] pwm: lpc32xx: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 073/115] pwm: lpss-*: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 074/115] pwm: mediatek: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 075/115] pwm: meson: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 076/115] pwm: microchip-core: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 077/115] pwm: mtk-disp: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 078/115] pwm: mxs: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 079/115] pwm: ntxec: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 080/115] pwm: omap-dmtimer: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 081/115] pwm: pca9685: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 082/115] pwm: pxa: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 083/115] pwm: raspberrypi-poe: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 084/115] pwm: rcar: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 085/115] pwm: renesas-tpu: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 086/115] pwm: rockchip: " Uwe Kleine-König
2023-12-06 13:06   ` Heiko Stübner
2023-12-06 11:44 ` [PATCH v4 087/115] pwm: rz-mtu3: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 088/115] pwm: samsung: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 089/115] pwm: sifive: " Uwe Kleine-König
2023-12-08  9:30   ` Emil Renner Berthing
2023-12-08  9:52     ` Uwe Kleine-König
2023-12-08  9:59       ` Emil Renner Berthing
2023-12-06 11:44 ` [PATCH v4 090/115] pwm: sl28cpld: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 091/115] pwm: spear: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 092/115] pwm: sprd: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 093/115] pwm: sti: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 094/115] pwm: stm32-lp: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 095/115] pwm: stm32: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 096/115] pwm: stmpe: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 097/115] pwm: sun4i: " Uwe Kleine-König
2023-12-06 17:11   ` Andre Przywara
2023-12-13 20:31   ` Jernej Škrabec
2023-12-06 11:44 ` [PATCH v4 098/115] pwm: sunplus: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 099/115] pwm: tegra: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 100/115] pwm: tiecap: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 101/115] pwm: twl-led: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 102/115] pwm: twl: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 103/115] pwm: visconti: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 104/115] pwm: vt8500: " Uwe Kleine-König
2023-12-06 11:44 ` [PATCH v4 105/115] pwm: xilinx: " Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 106/115] gpio: mvebu: " Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 107/115] drm/bridge: ti-sn65dsi86: " Uwe Kleine-König
2024-01-22 15:19   ` Robert Foss
2023-12-06 11:45 ` [PATCH v4 108/115] leds: qcom-lpg: " Uwe Kleine-König
2023-12-07 17:05   ` Lee Jones
2023-12-06 11:45 ` [PATCH v4 110/115] pwm: Ensure that pwm_chips are allocated using pwmchip_alloc() Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 111/115] pwm: Ensure a struct pwm has the same lifetime as its pwm_chip Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 112/115] pwm: Ensure the memory backing a PWM chip isn't freed while used Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 113/115] pwm: Add more locking Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 114/115] pwm: Make pwmchip_[sg]et_drvdata a wrapper around dev_set_drvdata Uwe Kleine-König
2023-12-06 11:45 ` [PATCH v4 115/115] WIP: pwm: Add support for pwmchip devices for faster and easier userspace access Uwe Kleine-König
2023-12-08 15:41 ` [PATCH v4 000/115] pwm: Fix lifetime issues for pwm_chips Thierry Reding
2023-12-08 18:50   ` Uwe Kleine-König
2023-12-11 11:33     ` Thierry Reding
2023-12-11 12:18       ` Uwe Kleine-König
2023-12-12 21:05       ` Uwe Kleine-König

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