-----Original Message----- From: Krzysztof Kozlowski krzk@kernel.org Sent: Tuesday, December 8, 2020 12:35 AM To: Krzysztof Kozlowski krzk@kernel.org; linux-arm- kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org; linux- kernel@vger.kernel.org Cc: Sylwester Nawrocki snawrocki@kernel.org; Marek Szyprowski m.szyprowski@samsung.com; Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com; Arnd Bergmann arnd@arndb.de; Chanwoo Choi cw00.choi@samsung.com; Alim Akhtar alim.akhtar@samsung.com; Pankaj Dubey pankaj.dubey@samsung.com; stable@vger.kernel.org Subject: [PATCH v2 2/4] soc: samsung: exynos-asv: handle reading revision register error

If regmap_read() fails, the product_id local variable will contain random

value

from the stack. Do not try to parse such value and fail the ASV driver

probe.

Fixes: 5ea428595cc5 ("soc: samsung: Add Exynos Adaptive Supply Voltage driver") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski krzk@kernel.org

---

drivers/soc/samsung/exynos-asv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/samsung/exynos-asv.c b/drivers/soc/samsung/exynos-asv.c index f653e3533f0f..5daeadc36382 100644 --- a/drivers/soc/samsung/exynos-asv.c +++ b/drivers/soc/samsung/exynos-asv.c @@ -129,7 +129,13 @@ static int exynos_asv_probe(struct platform_device *pdev) return PTR_ERR(asv->chipid_regmap); }

• regmap_read(asv->chipid_regmap, EXYNOS_CHIPID_REG_PRO_ID,

&product_id);

• ret = regmap_read(asv->chipid_regmap,

EXYNOS_CHIPID_REG_PRO_ID,

• 	  &product_id);
  

• if (ret < 0) {

• dev_err(&pdev->dev, "Cannot read revision from
  

ChipID: %d\n",

• 	ret);
  

• return -ENODEV;
  

• }

  switch (product_id & EXYNOS_MASK) { case 0xE5422000:

-- 2.25.1

Reviewed-by: Pankaj Dubey pankaj.dubey@samsung.com