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| author | Uwe Kleine-König <u.kleine-koenig@pengutronix.de> | 2021-11-10 11:49:48 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-08 15:40:23 +0300 |
| commit | c0b3c06414c39ef473a9274f173c3737ddb09d7b (patch) | |
| tree | 874b03b207ce384e6a8f80a773827fa95e5c9a0e | |
| parent | 2cd05c38a27bee7fb42aa4d43174d68ac55dac0f (diff) | |
| download | linux-c0b3c06414c39ef473a9274f173c3737ddb09d7b.tar.xz | |
pwm: lpc18xx-sct: Initialize driver data and hardware before pwmchip_add()
[ Upstream commit 0401f24cd238ae200a23a13925f98de3d2c883b8 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/pwm/pwm-lpc18xx-sct.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c index 5ff11145c1a3..9b15b6a79082 100644 --- a/drivers/pwm/pwm-lpc18xx-sct.c +++ b/drivers/pwm/pwm-lpc18xx-sct.c @@ -400,12 +400,6 @@ 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; @@ -415,14 +409,12 @@ 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; @@ -430,10 +422,16 @@ 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; |