Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-23 19:31:53 +00:00
Code Issues Packages Projects Releases Wiki Activity
0d6daba5fa
linux/drivers
History
Mattia Dongili 9c9a43ed27 [CPUFREQ] return error when failing to set minfreq 
I just stumbled on this bug/feature, this is how to reproduce it:

# echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
# echo 450000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
# echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# cpufreq-info -p
450000 450000 powersave
# echo 1800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq ; echo $?
0
# cpufreq-info -p
450000 450000 powersave

Here it is. The kernel refuses to set a min_freq higher than the
max_freq but it allows a max_freq lower than min_freq (lowering min_freq
also).

This behaviour is pretty straightforward (but undocumented) and it
doesn't return an error altough failing to accomplish the requested
action (set min_freq).
The problem (IMO) is basically that userspace is not allowed to set a
full policy atomically while the kernel always does that thus it must
enforce an ordering on operations.

The attached patch returns -EINVAL if trying to increase frequencies
starting from scaling_min_freq and documents the correct ordering of writes.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Dominik Brodowski <linux at dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>

--
2006-07-31 18:37:05 -04:00
..
acorn [PATCH] irq-flags: misc drivers: Use the new IRQF_ constants 2006-07-02 13:58:50 -07:00
acpi [PATCH] Revert "ACPI: execute Notify() handlers on new thread" 2006-07-12 21:02:24 -07:00
amba [PATCH] 64bit resource: fix up printks for resources in misc drivers 2006-06-27 09:23:59 -07:00
atm [ATM]: Typo in drivers/atm/Kconfig... 2006-07-08 13:30:09 -07:00
base [PATCH] cpu hotplug: use hotplug version of registration in late inits 2006-07-31 13:28:39 -07:00
block [PATCH] nbd: Abort request on data reception failure 2006-07-31 13:28:39 -07:00
bluetooth [Bluetooth] Enable SCO support for Broadcom HID proxy dongle 2006-07-24 12:44:34 -07:00
cdrom [PATCH] cdrom: fix bad cgc.buflen assignment 2006-07-10 13:24:15 -07:00
char [PATCH] hwrng: fix geode probe error unwind 2006-07-31 13:28:43 -07:00
clocksource [PATCH] GTOD: add scx200 HRT clocksource 2006-06-26 09:58:21 -07:00
connector [PATCH] Process Events: Fix biarch compatibility issue. use __u64 timestamp 2006-07-31 13:28:36 -07:00
cpufreq [CPUFREQ] return error when failing to set minfreq 2006-07-31 18:37:05 -04:00
crypto [CRYPTO] padlock: Fix alignment after aes_ctx rearrange 2006-07-15 11:08:50 +10:00
dio
dma [I/OAT]: Remove pci_module_init() from Intel I/OAT DMA engine 2006-07-21 14:50:13 -07:00
edac [PATCH] Fix and enable EDAC sysfs operation 2006-07-10 13:24:25 -07:00
eisa Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
fc4 [SCSI] More buffer->request_buffer changes 2006-07-14 09:41:13 -05:00
firmware Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
hwmon [PATCH] hwmon: Fix for first generation Abit uGuru chips 2006-07-12 15:43:07 -07:00
i2c [PATCH] pca9539: Honor the force parameter 2006-07-12 15:43:07 -07:00
ide Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2006-07-31 13:39:52 -07:00
ieee1394 [PATCH] lockdep: annotate ieee1394 skb-queue-head locking 2006-07-03 15:27:08 -07:00
infiniband IB/mthca: Initialize max_cmds before debug code prints it 2006-07-24 09:36:50 -07:00
input [PATCH] lockdep: annotate serio 2006-07-03 15:27:07 -07:00
isdn [PATCH] isdn: cleanup i_rdev udage 2006-07-10 13:24:27 -07:00
leds [PATCH] net48xx LED cleanups 2006-07-14 21:53:54 -07:00
macintosh Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2006-07-31 13:39:52 -07:00
mca
md [PATCH] md: fix oops in error-handling 2006-07-10 13:24:17 -07:00
media [PATCH] release_firmware() fixes 2006-07-10 13:24:15 -07:00
message Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6 2006-07-21 12:04:53 -07:00
mfd [ARM] 3727/1: fix ucb initialization on collie 2006-07-11 22:54:15 +01:00
misc [PATCH] irq-flags: misc drivers: Use the new IRQF_ constants 2006-07-02 13:58:50 -07:00
mmc [MMC] Change SDHCI version error to a warning 2006-07-13 16:17:46 +01:00
mtd Merge git://git.infradead.org/mtd-2.6 2006-07-03 21:29:08 -07:00
net Merge branch 'upstream' of git://electric-eye.fr.zoreil.com/home/romieu/linux-2.6 into upstream-fixes 2006-07-29 01:26:51 -04:00
nubus Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
oprofile [PATCH] oprofile: convert from semaphores to mutexes 2006-06-25 10:01:04 -07:00
parisc [PATCH] irq-flags: PARISC: Use the new IRQF_ constants 2006-07-02 13:58:52 -07:00
parport [PATCH] irq-flags: misc drivers: Use the new IRQF_ constants 2006-07-02 13:58:50 -07:00
pci [PATCH] pci/search: cleanups, add to kernel-api.tmpl 2006-07-31 13:28:40 -07:00
pcmcia [PATCH] pcmcia: fix ioctl GET_CONFIGURATION_INFO for pcmcia_cards 2006-07-31 13:28:41 -07:00
pnp [PATCH] Fix swsusp with PNP BIOS 2006-07-31 13:28:41 -07:00
rapidio Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
rtc [PATCH] RTC subsystem, Add ISL1208 support 2006-07-14 21:53:53 -07:00
s390 [S390] duplicate ccw devices in ccwgroup. 2006-07-27 14:00:33 +02:00
sbus [SPARC] sbus: Make sure sbus nodes are named uniquely. 2006-07-21 14:18:06 -07:00
scsi Merge branch 'master' into upstream-fixes 2006-07-29 01:39:17 -04:00
serial [SERIAL] sunzilog: Fix instance enumeration. 2006-07-21 14:18:25 -07:00
sh
sn [PATCH] irq-flags: misc drivers: Use the new IRQF_ constants 2006-07-02 13:58:50 -07:00
spi [PATCH] lockdep: annotate on-stack completions 2006-07-03 15:27:09 -07:00
tc [PATCH] irq-flags: misc drivers: Use the new IRQF_ constants 2006-07-02 13:58:50 -07:00
telephony Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/devfs-2.6 2006-06-29 14:19:21 -07:00
usb [PATCH] USB: move usb-serial.h to include/linux/usb/ 2006-07-12 16:03:25 -07:00
video Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2006-07-31 13:39:52 -07:00
w1 [PATCH] w1: remove drivers/w1/w1.h 2006-07-12 15:38:28 -07:00
zorro Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
Kconfig [I/OAT]: DMA memcpy subsystem 2006-06-17 21:18:43 -07:00
Makefile [PATCH] Time: i386 Clocksource Drivers 2006-06-26 09:58:21 -07:00