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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2021-11-10 09:49:48 +0100
committerThierry Reding <thierry.reding@gmail.com>2022-02-02 17:03:46 +0100
commit0401f24cd238ae200a23a13925f98de3d2c883b8 (patch)
tree4f44f5b0ee87b1a2d839e1b4f56fce49b3a9f68d /drivers/pwm
parent914195ec7ecb55e0be5404e3e0edc561888dd9f0 (diff)
pwm: lpc18xx-sct: Initialize driver data and hardware before pwmchip_add()
When a driver calls pwmchip_add() it has to be prepared to immediately get its callbacks called. So move allocation of driver data and hardware initialization before the call to pwmchip_add(). This fixes a potential NULL pointer exception and a race condition on register writes. Fixes: 841e6f90bb78 ("pwm: NXP LPC18xx PWM/SCT driver") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-lpc18xx-sct.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 8e461f3baa05..8cc8ae16553c 100644
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -395,12 +395,6 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
BIT(lpc18xx_pwm->period_event));
- ret = pwmchip_add(&lpc18xx_pwm->chip);
- if (ret < 0) {
- dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
- goto disable_pwmclk;
- }
-
for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
struct lpc18xx_pwm_data *data;
@@ -410,14 +404,12 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
- goto remove_pwmchip;
+ goto disable_pwmclk;
}
pwm_set_chip_data(pwm, data);
}
- platform_set_drvdata(pdev, lpc18xx_pwm);
-
val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
val &= ~LPC18XX_PWM_BIDIR;
val &= ~LPC18XX_PWM_CTRL_HALT;
@@ -425,10 +417,16 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
val |= LPC18XX_PWM_PRE(0);
lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);
+ ret = pwmchip_add(&lpc18xx_pwm->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
+ goto disable_pwmclk;
+ }
+
+ platform_set_drvdata(pdev, lpc18xx_pwm);
+
return 0;
-remove_pwmchip:
- pwmchip_remove(&lpc18xx_pwm->chip);
disable_pwmclk:
clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
return ret;