Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Sun, 12 Jun 2016 22:34:41 +0100 | Subject | [PATCH 3.2 18/46] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay |
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3.2.81-rc1 review patch. If anyone has any objections, please let me know.
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From: Stephen Boyd <sboyd@codeaurora.org>
commit eda5ecc0a6b865561997e177c393f0b0136fe3b7 upstream.
The trigger delay algorithm that converts from microseconds to the register value looks incorrect. According to most of the PMIC documentation, the equation is
delay (Seconds) = (1 / 1024) * 2 ^ (x + 4)
except for one case where the documentation looks to have a formatting issue and the equation looks like
delay (Seconds) = (1 / 1024) * 2 x + 4
Most likely this driver was written with the improper documentation to begin with. According to the downstream sources the valid delays are from 2 seconds to 1/64 second, and the latter equation just doesn't make sense for that. Let's fix the algorithm and the range check to match the documentation and the downstream sources.
Reported-by: Bjorn Andersson <bjorn.andersson@linaro.org> Fixes: 92d57a73e410 ("input: Add support for Qualcomm PMIC8XXX power key") Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: John Stultz <john.stultz@linaro.org> Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [bwh: Backported to 3.2: use pdata->kpd_trigger_delay_us not kpd_delay] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- --- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -98,7 +98,9 @@ static int __devinit pmic8xxx_pwrkey_pro return -EINVAL; } - if (pdata->kpd_trigger_delay_us > 62500) { + /* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */ + if (pdata->kpd_trigger_delay_us > USEC_PER_SEC * 2 || + pdata->kpd_trigger_delay_us < USEC_PER_SEC / 64) { dev_err(&pdev->dev, "invalid power key trigger delay\n"); return -EINVAL; } @@ -120,8 +122,8 @@ static int __devinit pmic8xxx_pwrkey_pro pwr->phys = "pmic8xxx_pwrkey/input0"; pwr->dev.parent = &pdev->dev; - delay = (pdata->kpd_trigger_delay_us << 10) / USEC_PER_SEC; - delay = 1 + ilog2(delay); + delay = (pdata->kpd_trigger_delay_us << 6) / USEC_PER_SEC; + delay = ilog2(delay); err = pm8xxx_readb(pdev->dev.parent, PON_CNTL_1, &pon_cntl); if (err < 0) {
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