| Message ID | 20240603-mtk-thermal-calib-check-v1-1-5d6bf040414c@baylibre.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | thermal/drivers/mediatek/lvts_thermal: Return error in case of invalid efuse data | expand |
On Mon, 3 Jun 2024, Julien Panis wrote: > This patch prevents from registering thermal entries and letting the > driver misbehave if efuse data is invalid. A device is not properly > calibrated if the golden temperature is zero. > > Signed-off-by: Julien Panis <jpanis@baylibre.com> Reviewed-by: Nicolas Pitre <npitre@baylibre.com> > --- > Guard against invalid calibration data, following this discussion: > https://lore.kernel.org/all/ad047631-16b8-42ce-8a8d-1429e6af4517@collabora.com/ > --- > drivers/thermal/mediatek/lvts_thermal.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c > index 0bb3a495b56e..185d5a32711f 100644 > --- a/drivers/thermal/mediatek/lvts_thermal.c > +++ b/drivers/thermal/mediatek/lvts_thermal.c > @@ -769,7 +769,11 @@ static int lvts_golden_temp_init(struct device *dev, u8 *calib, > */ > gt = (((u32 *)calib)[0] >> lvts_data->gt_calib_bit_offset) & 0xff; > > - if (gt && gt < LVTS_GOLDEN_TEMP_MAX) > + /* A zero value for gt means that device has invalid efuse data */ > + if (!gt) > + return -ENODATA; > + > + if (gt < LVTS_GOLDEN_TEMP_MAX) > golden_temp = gt; > > golden_temp_offset = golden_temp * 500 + lvts_data->temp_offset; > > --- > base-commit: 632483ea8004edfadd035de36e1ab2c7c4f53158 > change-id: 20240603-mtk-thermal-calib-check-ba2ec24a1c32 > > Best regards, > -- > Julien Panis <jpanis@baylibre.com> > >
On 03/06/2024 14:06, Julien Panis wrote: > This patch prevents from registering thermal entries and letting the > driver misbehave if efuse data is invalid. A device is not properly > calibrated if the golden temperature is zero. > > Signed-off-by: Julien Panis <jpanis@baylibre.com> > --- Applied, thanks
Il 03/06/24 14:06, Julien Panis ha scritto: > This patch prevents from registering thermal entries and letting the > driver misbehave if efuse data is invalid. A device is not properly > calibrated if the golden temperature is zero. > > Signed-off-by: Julien Panis <jpanis@baylibre.com> Fixes tag, please. Regards, Angelo > --- > Guard against invalid calibration data, following this discussion: > https://lore.kernel.org/all/ad047631-16b8-42ce-8a8d-1429e6af4517@collabora.com/ > --- > drivers/thermal/mediatek/lvts_thermal.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c > index 0bb3a495b56e..185d5a32711f 100644 > --- a/drivers/thermal/mediatek/lvts_thermal.c > +++ b/drivers/thermal/mediatek/lvts_thermal.c > @@ -769,7 +769,11 @@ static int lvts_golden_temp_init(struct device *dev, u8 *calib, > */ > gt = (((u32 *)calib)[0] >> lvts_data->gt_calib_bit_offset) & 0xff; > > - if (gt && gt < LVTS_GOLDEN_TEMP_MAX) > + /* A zero value for gt means that device has invalid efuse data */ > + if (!gt) > + return -ENODATA; > + > + if (gt < LVTS_GOLDEN_TEMP_MAX) > golden_temp = gt; > > golden_temp_offset = golden_temp * 500 + lvts_data->temp_offset; > > --- > base-commit: 632483ea8004edfadd035de36e1ab2c7c4f53158 > change-id: 20240603-mtk-thermal-calib-check-ba2ec24a1c32 > > Best regards,
On Tue, 4 Jun 2024, AngeloGioacchino Del Regno wrote: > Il 03/06/24 14:06, Julien Panis ha scritto: > > This patch prevents from registering thermal entries and letting the > > driver misbehave if efuse data is invalid. A device is not properly > > calibrated if the golden temperature is zero. > > > > Signed-off-by: Julien Panis <jpanis@baylibre.com> > > Fixes tag, please. What should it refer to? This is arguably a robustness enhancement for a defficiency that has been there all along. Nicolas
Il 04/06/24 18:33, Nicolas Pitre ha scritto: > On Tue, 4 Jun 2024, AngeloGioacchino Del Regno wrote: > >> Il 03/06/24 14:06, Julien Panis ha scritto: >>> This patch prevents from registering thermal entries and letting the >>> driver misbehave if efuse data is invalid. A device is not properly >>> calibrated if the golden temperature is zero. >>> >>> Signed-off-by: Julien Panis <jpanis@baylibre.com> >> >> Fixes tag, please. > > What should it refer to? This is arguably a robustness enhancement for a > defficiency that has been there all along. > > If that's been there since day 1, the fixes tag should be the day 1 commit, of course. I see that as an important bugfix and not just a robustness enhancement, as SoCs with uncalibrated LVTS would *not work*, as the kernel would shut down the system before even loading the userspace. Regards, Angelo
diff --git a/drivers/thermal/mediatek/lvts_thermal.c b/drivers/thermal/mediatek/lvts_thermal.c index 0bb3a495b56e..185d5a32711f 100644 --- a/drivers/thermal/mediatek/lvts_thermal.c +++ b/drivers/thermal/mediatek/lvts_thermal.c @@ -769,7 +769,11 @@ static int lvts_golden_temp_init(struct device *dev, u8 *calib, */ gt = (((u32 *)calib)[0] >> lvts_data->gt_calib_bit_offset) & 0xff; - if (gt && gt < LVTS_GOLDEN_TEMP_MAX) + /* A zero value for gt means that device has invalid efuse data */ + if (!gt) + return -ENODATA; + + if (gt < LVTS_GOLDEN_TEMP_MAX) golden_temp = gt; golden_temp_offset = golden_temp * 500 + lvts_data->temp_offset;
This patch prevents from registering thermal entries and letting the driver misbehave if efuse data is invalid. A device is not properly calibrated if the golden temperature is zero. Signed-off-by: Julien Panis <jpanis@baylibre.com> --- Guard against invalid calibration data, following this discussion: https://lore.kernel.org/all/ad047631-16b8-42ce-8a8d-1429e6af4517@collabora.com/ --- drivers/thermal/mediatek/lvts_thermal.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- base-commit: 632483ea8004edfadd035de36e1ab2c7c4f53158 change-id: 20240603-mtk-thermal-calib-check-ba2ec24a1c32 Best regards,