Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-25 20:32:22 +00:00
Code Issues Packages Projects Releases Wiki Activity
9556f9dad8
linux/drivers/clk
History
Brian Norris 9556f9dad8 clk: divider: handle integer overflow when dividing large clock rates 
On 32-bit architectures, 'unsigned long' (the type used to hold clock
rates, in Hz) is often only 32 bits wide. DIV_ROUND_UP() (as used in,
e.g., commit b11d282dbe "clk: divider: fix rate calculation for
fractional rates") can yield an integer overflow on clock rates that are
not (by themselves) too large to fit in 32 bits, because it performs
addition before the division. See for example:

  DIV_ROUND_UP(3000000000, 1500000000) = (3.0G + 1.5G - 1) / 1.5G
                                       = OVERFLOW / 1.5G

This patch fixes such cases by always promoting the dividend to 64-bits
(unsigned long long) before doing the division. While this patch does
not resolve the issue with large clock rates across the common clock
framework nor address the problems with doing full 64-bit arithmetic on
a 32-bit architecture, it does fix some issues seen when using clock
dividers on a 3GHz reference clock to produce a 1.5GHz CPU clock for an
ARMv7 Brahma B15 SoC.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reference: http://lkml.kernel.org/g/20150413201433.GQ32500@ld-irv-0074
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2015-09-16 15:22:33 -07:00
..
at91 clk: at91: system: don't try to free_irq when there is no IRQ 2015-09-16 15:22:22 -07:00
bcm clk: bcm: Convert to clk_hw based provider APIs 2015-08-24 16:48:48 -07:00
berlin clk: Convert __clk_get_name(hw->clk) to clk_hw_get_name(hw) 2015-08-24 16:49:12 -07:00
h8300 clk: h8s2678: Fix compile error 2015-09-02 17:07:10 -07:00
hisilicon clk: Hi6220: separately build stub clock driver 2015-09-03 10:44:55 -07:00
imx Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-08-31 17:38:39 -07:00
ingenic clk: ingenic: Include clk.h 2015-07-20 11:11:36 -07:00
keystone Merge branch 'cleanup-clk-h-includes' into clk-next 2015-07-28 11:59:09 -07:00
mediatek Merge branch 'cleanup-clk-h-includes' into clk-next 2015-07-28 11:59:09 -07:00
meson clk: meson8b: Properly include clk.h 2015-07-20 10:53:10 -07:00
mmp clk: mmp: Convert to clk_hw based provider APIs 2015-08-24 16:48:49 -07:00
mvebu clk: mvebu: Convert to clk_hw based provider APIs 2015-08-24 16:48:50 -07:00
mxs clk: mxs: Include clk.h in C files that use it 2015-07-20 11:11:07 -07:00
nxp clk: nxp: Remove clk.h include 2015-07-20 11:11:08 -07:00
pistachio clk: pistachio: correct critical clock list 2015-08-26 11:34:43 -07:00
pxa The clk framework changes for 4.3 are mostly updates to existing drivers 2015-08-31 17:26:48 -07:00
qcom clk: qcom: Allow clk_set_parent() to work on display clocks 2015-09-16 15:22:18 -07:00
rockchip Merge branch 'clk-next' into v4.3-rc1 2015-09-16 15:20:03 -07:00
samsung ARM: SoC: late fixes and dependencies 2015-09-10 17:59:04 -07:00
shmobile Merge branch 'i2c/for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2015-09-08 16:16:26 -07:00
sirf clk: atlas7: fix pll missed divide NR in fraction mode 2015-08-24 16:49:08 -07:00
socfpga clk: socfpga: Add a second parent option for the dbg_base_clk 2015-08-24 16:49:03 -07:00
spear The clk framework changes for 4.3 are mostly updates to existing drivers 2015-08-31 17:26:48 -07:00
st clk: Convert __clk_get_name(hw->clk) to clk_hw_get_name(hw) 2015-08-24 16:49:12 -07:00
sunxi clk: sunxi: sun9i-mmc: Fix module autoload for OF platform driver 2015-09-16 15:22:31 -07:00
tegra clk: tegra: dfll: Properly protect OPP list 2015-09-16 15:16:03 -07:00
ti ARM: DT updates for v4.3 2015-09-01 13:09:20 -07:00
ux500 clk/ARM: move Ux500 PRCC bases to the device tree 2015-08-24 16:49:14 -07:00
versatile drivers/clk: appropriate __init annotation for const data 2015-08-24 16:59:32 -07:00
x86 clk: x86: drop owner assignment from platform_drivers 2014-10-20 16:20:23 +02:00
zte clk: zx: Constify parent names in clock init data 2015-07-28 11:59:39 -07:00
zynq ARM: SoC platform updates for v4.3 2015-09-01 12:18:40 -07:00
clk-asm9260.c clk: asm9260: Fix of_io_request_and_map error check 2015-05-13 12:32:52 -07:00
clk-axi-clkgen.c clk: axi-clkgen: Remove clk.h include 2015-07-20 10:52:50 -07:00
clk-axm5516.c clk: axm55xx: Use %zu in pr_info for size_t 2015-05-13 12:32:53 -07:00
clk-bcm2835.c clk: bcm2835: Drop the fixed sys_pclk. 2015-08-12 00:59:20 -07:00
clk-cdce706.c clk: Convert __clk_get_flags() to clk_hw_get_flags() 2015-08-24 16:48:44 -07:00
clk-cdce925.c clk: cdce925: Include clk.h 2015-07-20 11:11:32 -07:00
clk-clps711x.c clk: clps711x: Remove clk.h include 2015-07-20 10:52:53 -07:00
clk-composite.c clk: Convert basic types to clk_hw based provider APIs 2015-08-24 16:48:48 -07:00
clk-conf.c clk: clk-conf: Fix typo in comment 2015-05-21 11:55:05 -07:00
clk-devres.c
clk-divider.c clk: divider: handle integer overflow when dividing large clock rates 2015-09-16 15:22:33 -07:00
clk-efm32gg.c clk: efm32gg: Remove clk.h include 2015-07-20 10:52:54 -07:00
clk-fixed-factor.c clk: Convert basic types to clk_hw based provider APIs 2015-08-24 16:48:48 -07:00
clk-fixed-rate.c clk: basic-types: Remove useless allocation failure printks 2015-05-14 16:51:50 -07:00
clk-fractional-divider.c clk: basic-type: Silence warnings about lock imbalances 2015-07-28 11:59:28 -07:00
clk-gate.c clk: basic-type: Silence warnings about lock imbalances 2015-07-28 11:59:28 -07:00
clk-gpio.c clk: gpio: Mark parent_names array const 2015-07-28 11:59:24 -07:00
clk-highbank.c clk: highbank: Include clk.h 2015-07-20 11:11:22 -07:00
clk-ls1x.c clk: ls1x: Fix duplicate const for parent names 2015-05-05 22:50:50 -07:00
clk-max77686.c drivers/clk: include <module.h> for clk-max77xxx modular code 2015-06-16 14:12:25 -04:00
clk-max77802.c drivers/clk: include <module.h> for clk-max77xxx modular code 2015-06-16 14:12:25 -04:00
clk-max-gen.c clk: max-gen: Silence sparse warnings 2015-05-14 17:11:18 -07:00
clk-max-gen.h clk: Add generic driver for Maxim PMIC clocks 2014-09-09 13:55:44 -07:00
clk-mb86s7x.c clk: Add clock driver for mb86s7x 2015-04-10 13:51:55 -07:00
clk-moxart.c clk: moxart: Include clk.h 2015-07-20 11:11:33 -07:00
clk-mux.c clk: Replace __clk_get_num_parents with clk_hw_get_num_parents() 2015-08-24 16:48:43 -07:00
clk-nomadik.c clk: nomadik: Remove clk.h and clkdev.h includes 2015-07-20 10:52:57 -07:00
clk-nspire.c
clk-palmas.c clk: palmas: Remove clkdev.h includes 2015-07-20 10:52:58 -07:00
clk-pwm.c clk: Add PWM clock driver 2015-04-10 14:44:43 -07:00
clk-qoriq.c clk: qoriq: Add support for the platform PLL 2015-02-18 09:56:43 -08:00
clk-rk808.c clk: rk808: Remove clk.h include 2015-07-20 10:53:00 -07:00
clk-s2mps11.c clk: s2mps11: Use kcalloc instead of kzalloc for array allocation 2015-07-28 11:59:32 -07:00
clk-si570.c clk: si570: Include clk.h 2015-07-20 11:11:35 -07:00
clk-si5351.c clk: si5351: Convert __clk_get_name() to clk_hw_get_name() 2015-08-24 16:49:01 -07:00
clk-si5351.h
clk-stm32f4.c clk: stm32f4: Convert to clk_hw based provider APIs 2015-08-24 16:48:51 -07:00
clk-twl6040.c Merge branch 'cleanup-clk-h-includes' into clk-next 2015-07-28 11:59:09 -07:00
clk-u300.c clk: u300: Remove clk.h include 2015-07-20 10:53:04 -07:00
clk-vt8500.c
clk-wm831x.c clk: wm831x: Remove clk.h include 2015-07-20 10:53:05 -07:00
clk-xgene.c clk: Convert __clk_get_name(hw->clk) to clk_hw_get_name(hw) 2015-08-24 16:49:12 -07:00
clk.c clk: remove duplicated code with __clk_set_parent_after 2015-08-24 16:49:13 -07:00
clk.h clk: Replace of_clk_get_by_clkspec() with of_clk_get_from_provider() 2015-03-12 12:20:34 -07:00
clkdev.c clkdev: add clkdev_create() helper 2015-05-06 11:58:57 +01:00
Kconfig clk: tegra: Changes for v4.2-rc1 2015-06-20 13:29:48 -07:00
Makefile clk: Rename clk-gpio-gate.c to clk-gpio.c 2015-07-06 17:20:55 -07:00