From 8486a92a0f54ec06435333258fb3e35dd8ab7430 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Mon, 28 Mar 2016 13:09:56 +0900 Subject: regulator: s2mps11: Fix invalid selector mask and voltages for buck9 [ Upstream commit 3b672623079bb3e5685b8549e514f2dfaa564406 ] The buck9 regulator of S2MPS11 PMIC had incorrect vsel_mask (0xff instead of 0x1f) thus reading entire register as buck9's voltage. This effectively caused regulator core to interpret values as higher voltages than they were and then to set real voltage much lower than intended. The buck9 provides power to other regulators, including LDO13 and LDO19 which supply the MMC2 (SD card). On Odroid XU3/XU4 the lower voltage caused SD card detection errors on Odroid XU3/XU4: mmc1: card never left busy state mmc1: error -110 whilst initialising SD card During driver probe the regulator core was checking whether initial voltage matches the constraints. With incorrect vsel_mask of 0xff and default value of 0x50, the core interpreted this as 5 V which is outside of constraints (3-3.775 V). Then the regulator core was adjusting the voltage to match the constraints. With incorrect vsel_mask this new voltage mapped to a vere low voltage in the driver. Signed-off-by: Krzysztof Kozlowski Reviewed-by: Javier Martinez Canillas Tested-by: Javier Martinez Canillas Signed-off-by: Mark Brown Cc: Signed-off-by: Sasha Levin --- include/linux/mfd/samsung/s2mps11.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/mfd/samsung/s2mps11.h b/include/linux/mfd/samsung/s2mps11.h index 7981a9d77d3f..ad81a1a7193f 100644 --- a/include/linux/mfd/samsung/s2mps11.h +++ b/include/linux/mfd/samsung/s2mps11.h @@ -173,10 +173,12 @@ enum s2mps11_regulators { #define S2MPS11_LDO_VSEL_MASK 0x3F #define S2MPS11_BUCK_VSEL_MASK 0xFF +#define S2MPS11_BUCK9_VSEL_MASK 0x1F #define S2MPS11_ENABLE_MASK (0x03 << S2MPS11_ENABLE_SHIFT) #define S2MPS11_ENABLE_SHIFT 0x06 #define S2MPS11_LDO_N_VOLTAGES (S2MPS11_LDO_VSEL_MASK + 1) #define S2MPS11_BUCK_N_VOLTAGES (S2MPS11_BUCK_VSEL_MASK + 1) +#define S2MPS11_BUCK9_N_VOLTAGES (S2MPS11_BUCK9_VSEL_MASK + 1) #define S2MPS11_RAMP_DELAY 25000 /* uV/us */ -- cgit v1.2.3 From c07b2d4fbd9b8773f1dc4ed596f5d4bd82cc7217 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 2 May 2016 12:46:42 -0700 Subject: Minimal fix-up of bad hashing behavior of hash_64() [ Upstream commit 689de1d6ca95b3b5bd8ee446863bf81a4883ea25 ] This is a fairly minimal fixup to the horribly bad behavior of hash_64() with certain input patterns. In particular, because the multiplicative value used for the 64-bit hash was intentionally bit-sparse (so that the multiply could be done with shifts and adds on architectures without hardware multipliers), some bits did not get spread out very much. In particular, certain fairly common bit ranges in the input (roughly bits 12-20: commonly with the most information in them when you hash things like byte offsets in files or memory that have block factors that mean that the low bits are often zero) would not necessarily show up much in the result. There's a bigger patch-series brewing to fix up things more completely, but this is the fairly minimal fix for the 64-bit hashing problem. It simply picks a much better constant multiplier, spreading the bits out a lot better. NOTE! For 32-bit architectures, the bad old hash_64() remains the same for now, since 64-bit multiplies are expensive. The bigger hashing cleanup will replace the 32-bit case with something better. The new constants were picked by George Spelvin who wrote that bigger cleanup series. I just picked out the constants and part of the comment from that series. Cc: stable@vger.kernel.org Cc: George Spelvin Cc: Thomas Gleixner Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/hash.h | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/hash.h b/include/linux/hash.h index d0494c399392..a75b1009d3f7 100644 --- a/include/linux/hash.h +++ b/include/linux/hash.h @@ -33,12 +33,28 @@ #error Wordsize not 32 or 64 #endif +/* + * The above primes are actively bad for hashing, since they are + * too sparse. The 32-bit one is mostly ok, the 64-bit one causes + * real problems. Besides, the "prime" part is pointless for the + * multiplicative hash. + * + * Although a random odd number will do, it turns out that the golden + * ratio phi = (sqrt(5)-1)/2, or its negative, has particularly nice + * properties. + * + * These are the negative, (1 - phi) = (phi^2) = (3 - sqrt(5))/2. + * (See Knuth vol 3, section 6.4, exercise 9.) + */ +#define GOLDEN_RATIO_32 0x61C88647 +#define GOLDEN_RATIO_64 0x61C8864680B583EBull + static __always_inline u64 hash_64(u64 val, unsigned int bits) { u64 hash = val; -#if defined(CONFIG_ARCH_HAS_FAST_MULTIPLIER) && BITS_PER_LONG == 64 - hash = hash * GOLDEN_RATIO_PRIME_64; +#if BITS_PER_LONG == 64 + hash = hash * GOLDEN_RATIO_64; #else /* Sigh, gcc can't optimise this alone like it does for 32 bits. */ u64 n = hash; -- cgit v1.2.3