| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 093/175] power: supply: max17042: handle fails of reading status register | Date | Mon, 20 Sep 2021 18:42:22 +0200 |
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From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
commit 54784ffa5b267f57161eb8fbb811499f22a0a0bf upstream.
Reading status register can fail in the interrupt handler. In such case, the regmap_read() will not store anything useful under passed 'val' variable and random stack value will be used to determine type of interrupt.
Handle the regmap_read() failure to avoid handling interrupt type and triggering changed power supply event based on random stack value.
Fixes: 39e7213edc4f ("max17042_battery: Support regmap to access device's registers") Cc: <stable@vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/power/supply/max17042_battery.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/power/supply/max17042_battery.c +++ b/drivers/power/supply/max17042_battery.c @@ -760,8 +760,12 @@ static irqreturn_t max17042_thread_handl { struct max17042_chip *chip = dev; u32 val; + int ret; + + ret = regmap_read(chip->regmap, MAX17042_STATUS, &val); + if (ret) + return IRQ_HANDLED; - regmap_read(chip->regmap, MAX17042_STATUS, &val); if ((val & STATUS_INTR_SOCMIN_BIT) || (val & STATUS_INTR_SOCMAX_BIT)) { dev_info(&chip->client->dev, "SOC threshold INTR\n");
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