kernel-ark/drivers/char
Nils Carlson ae21cf9248 hpet: hpet driver periodic timer setup bug fixes
The periodic interrupt from drivers/char/hpet.c does not work correctly,
both when using the periodic capability of the hardware and while
emulating the periodic interrupt (when hardware does not support periodic
mode).

With timers capable of periodic interrupts, the comparator field is first
set with the period value followed by set of hidden accumulator, which has
the side effect of overwriting the comparator value.  This results in
wrong periodicity for the interrupts.  For, periodic interrupts to work,
following steps are necessary, in that order.

* Set config with Tn_VAL_SET_CNF bit

* Write to hidden accumulator, the value written is the time when the
  first interrupt should be generated

* Write compartor with period interval for subsequent interrupts
  (http://www.intel.com/hardwaredesign/hpetspec_1.pdf )

When emulating periodic timer with timers not capable of periodic
interrupt, driver is adding the period to counter value instead of
comparator value, which causes slow drift when using this emulation.

Also, driver seems to add hpetp->hp_delta both while setting up periodic
interrupt and while emulating periodic interrupts with timers not capable
of doing periodic interrupts.  This hp_delta will result in slower than
expected interrupt rate and should not be used while setting the interval.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24 07:21:03 -07:00
..
agp Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2009-09-23 09:32:11 -07:00
hw_random virtio: add virtio IDs file 2009-09-23 22:26:32 +09:30
ip2 tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
ipmi trivial: add __init macro/ fix of __exit macro location in ipmi_poweroff.c 2009-09-21 15:14:58 +02:00
mwave mwave: fix read buffer overflow 2009-09-24 07:21:03 -07:00
pcmcia pcmcia: fix read buffer overflow 2009-09-22 07:17:42 -07:00
rio headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
tpm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-09-23 15:18:57 -07:00
xilinx_hwicap xilinx_hwicap: remove improper wording in license statement 2008-12-17 11:23:07 -08:00
.gitignore
amiserial.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
apm-emulation.c
applicom.c applicom: Auto-load applicom module when device opened. 2009-04-06 14:36:30 -07:00
applicom.h
bfin_jtag_comm.c bfin_jtag_comm: clean up printk usage 2009-06-22 11:32:23 -07:00
bfin-otp.c
briq_panel.c
bsr.c powerpc/BSR: Fix BSR to allow mmap of small BSR on 64k kernel 2009-06-26 14:37:26 +10:00
cd1865.h
ChangeLog
consolemap.c consolemap: indentation & braces disagree - reindent 2009-01-06 15:59:30 -08:00
cp437.uni unicode table for cp437 2008-12-13 11:25:49 -08:00
cs5535_gpio.c
cyclades.c serial: move delta_msr_wait into the tty_port 2009-09-19 13:13:31 -07:00
defkeymap.c_shipped
defkeymap.map
digi1.h
digiFep1.h
digiPCI.h
ds1302.c rtc: use bcd2bin/bin2bcd 2008-10-20 08:52:41 -07:00
ds1620.c [ARM] netwinder: clean up GPIO naming 2008-12-13 09:12:07 +00:00
dsp56k.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
dtlk.c dtlk: off by one in {read,write}_tts() 2009-06-19 16:46:06 -07:00
efirtc.c
epca.c trivial: remove unnecessary semicolons 2009-09-21 15:14:58 +02:00
epca.h
epcaconfig.h
esp.c serial: move delta_msr_wait into the tty_port 2009-09-19 13:13:31 -07:00
generic_nvram.c powerpc/nvram: Enable use Generic NVRAM driver for different size chips 2009-09-11 16:02:11 +10:00
generic_serial.c tty: Remove some pointless casts 2009-01-02 10:19:40 -08:00
genrtc.c
hangcheck-timer.c
hpet.c hpet: hpet driver periodic timer setup bug fixes 2009-09-24 07:21:03 -07:00
hvc_beat.c powerpc/cell: Use correct types in beat files 2009-01-08 16:25:16 +11:00
hvc_console.c hvc_console: Drop unnecessary NULL test 2009-08-20 10:29:23 +10:00
hvc_console.h powerpc: Make open count variables signed in hvcs/hvsi/hvc_console 2008-12-03 21:04:13 +11:00
hvc_irq.c hvc_console: Call free_irq() only if request_irq() was successful 2009-01-13 14:48:01 +11:00
hvc_iseries.c drivers/hvc: Add missing __devexit_p() 2009-06-16 14:15:44 +10:00
hvc_iucv.c [S390] proper use of device register 2009-09-11 10:29:45 +02:00
hvc_rtas.c
hvc_udbg.c powerpc: udbg-based backend for hvc_console 2008-11-19 16:04:25 +11:00
hvc_vio.c hvc_console: Add __init and __exit to hvc_vio 2009-08-28 14:24:11 +10:00
hvc_xen.c hvc_console: Add a hangup notifier for backends 2008-10-22 10:59:54 +11:00
hvcs.c Merge commit 'origin/master' into next 2009-06-18 11:16:55 +10:00
hvsi.c powerpc/hvsi: Avoid calculating possibly-invalid address 2009-08-20 10:29:28 +10:00
i8k.c i8k: Add Dell Vostro systems 2009-01-02 10:28:32 -08:00
isicom.c isicom: split the open method for the isicom device 2009-09-19 13:13:27 -07:00
istallion.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
Kconfig MIPS: Update VR41xx GPIO driver to use gpiolib 2009-07-03 15:45:25 +01:00
keyboard.c Input: keyboard - remove warning about raw mode not supported 2009-04-20 21:21:24 -07:00
lp.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
Makefile MIPS: Update VR41xx GPIO driver to use gpiolib 2009-07-03 15:45:25 +01:00
mbcs.c [IA64] mbcs: fix printk format warnings 2009-09-15 08:42:00 -07:00
mbcs.h
mem.c /dev/zero: avoid repeated access_ok() checks 2009-09-24 07:21:03 -07:00
misc.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
mmtimer.c
moxa.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
moxa.h
mspec.c
mxser.c tty: Char: mxser, use THRE for ASPP_OQUEUE ioctl 2009-09-19 13:13:38 -07:00
mxser.h
n_hdlc.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
n_r3964.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
n_tty.c n_tty: move echoctl check and clean up logic 2009-09-19 13:13:34 -07:00
nozomi.c tty: fix chars_in_buffers 2009-07-20 16:38:43 -07:00
nsc_gpio.c
nvram.c [PATCH] nvram - convert PRINT_PROC to seq_file 2008-11-11 09:56:00 +00:00
nwbutton.c
nwbutton.h
nwflash.c [ARM] netwinder: clean up GPIO naming 2008-12-13 09:12:07 +00:00
pc8736x_gpio.c pc8736x_gpio: add support for PC87365 chips 2008-10-20 08:52:40 -07:00
ppdev.c ppdev: reduce kernel log spam 2009-06-18 13:03:54 -07:00
ps3flash.c ps3flash: Always read chunks of 256 KiB, and cache them 2009-06-15 16:47:27 +10:00
pty.c pty_write: don't do a tty_wakeup() when the buffers are full 2009-09-18 07:05:58 -07:00
random.c random: Add optional continuous repetition test to entropy store based rngs 2009-06-18 19:50:21 +08:00
raw.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
riscom8_reg.h
riscom8.c tty: riscom8, fix tty refcnt 2009-09-19 13:13:37 -07:00
riscom8.h
rocket_int.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rocket.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
rocket.h tty: rocketport uses different port flags to everyone else 2009-01-02 10:19:39 -08:00
rtc.c RTC: Remove the BKL. 2009-01-08 16:44:03 -07:00
scc.h m68k: atari - Rename "mfp" to "st_mfp" 2009-02-22 09:23:02 -08:00
scx200_gpio.c
selection.c tty: rewrite the ldisc locking 2009-06-11 08:51:01 -07:00
ser_a2232.c m68k: ser_a2232 - Kill warn_unused_result warnings 2009-01-12 20:56:39 +01:00
ser_a2232.h
ser_a2232fw.ax
ser_a2232fw.h
serial167.c cleanup console_print() 2009-09-14 17:41:42 -07:00
snsc_event.c
snsc.c device create: char: convert device_create_drvdata to device_create 2008-10-16 09:24:42 -07:00
snsc.h
sonypi.c Rationalize fasync return values 2009-03-16 08:34:35 -06:00
specialix_io8.h
specialix.c specialix.c: convert nested spin_lock_irqsave to spin_lock 2009-07-20 16:38:43 -07:00
stallion.c tty: Add carrier processing on close to the tty_port core 2009-06-11 08:50:56 -07:00
sx.c headers: smp_lock.h redux 2009-07-12 12:22:34 -07:00
sx.h
sxboards.h
sxwindow.h
synclink_gt.c hdlc: convert to netdev_tx_t 2009-09-01 01:13:31 -07:00
synclink.c hdlc: convert to netdev_tx_t 2009-09-01 01:13:31 -07:00
synclinkmp.c hdlc: convert to netdev_tx_t 2009-09-01 01:13:31 -07:00
sysrq.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
tb0219.c Update Yoichi Yuasa's e-mail address 2009-07-03 15:45:29 +01:00
tlclk.c
toshiba.c
tty_audit.c tty: remove buffer special casing 2009-06-11 08:51:02 -07:00
tty_buffer.c pty: avoid forcing 'low_latency' tty flag 2009-07-29 12:15:56 -07:00
tty_io.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6 2009-09-20 15:55:39 -07:00
tty_ioctl.c tty: vt: use printk_once 2009-09-19 13:13:35 -07:00
tty_ldisc.c tty-ldisc: get rid of tty_ldisc_try_get() helper function 2009-09-19 13:13:10 -07:00
tty_port.c TTY: fix typos 2009-09-19 13:13:36 -07:00
vc_screen.c vc: create vcs(a) devices for consoles 2009-07-20 16:38:43 -07:00
viotape.c tape: beyond ARRAY_SIZE of viocd_diskinfo 2009-06-02 10:32:34 +10:00
virtio_console.c virtio: add virtio IDs file 2009-09-23 22:26:32 +09:30
vme_scc.c m68k: vme_scc - Kill warn_unused_result warnings 2009-01-12 20:56:38 +01:00
vt_ioctl.c tty: Power: fix suspend vt regression 2009-09-19 13:13:35 -07:00
vt.c tty: vt: use printk_once 2009-09-19 13:13:35 -07:00