linux/drivers
Tejun Heo 8e16f94122 [PATCH] ahci: do not powerdown during initialization
ahci_init_controller() calls ahci_deinit_port() to make sure the
controller is stopped before initializing the controller.  In turn,
ahci_deinit_port() invokes ahci_power_down() to power down the port.
If the controller supports slumber mode, the link is put into it.

Unfortunately, some devices don't implement link powersaving mode
properly and show erratic behavior after link is put into slumber
mode.  For example, HL-DT-ST DVD-RAM GSA-H30N completely locks up on
slumber transition and can only be recovered with the *REAL* hard
reset - power removal and reapply.

Note that this makes the first probing reset different from all
others.  If the above dvd-ram is hotplugged after ahci is initialized,
no problem occurs because ahci is already fully initialized with phy
powered up.  So, this might also be the reason for other weird AHCI
initial probing abnormalities.

This patch moves power up/down out of port init/deinit and call them
only when needed.

Power down is now called only when suspending.  As system suspend
usually involves powering down 12v for storage devices, this shouldn't
cause problem even if the attached device doesn't support slumber
mode.  However, in partial power management and suspend failure cases,
devices might lock up after suspend attempt.  I thought about removing
transition to slumber mode altogether but ahci spec mandates it before
HBA D3 state transition.  Blacklisting such devices might be the
solution.

Signed-off-by: Tejun Heo <htejun@gmail.com>
2006-12-03 17:56:29 +09:00
..
acorn
acpi ACPI: Change ACPI to use dev_archdata instead of firmware_data 2006-12-01 14:52:01 -08:00
amba
ata [PATCH] ahci: do not powerdown during initialization 2006-12-03 17:56:29 +09:00
atm Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
base Driver core: platform_driver_probe(), can save codespace 2006-12-01 14:52:02 -08:00
block
bluetooth
cdrom [PATCH] block: support larger block pc requests 2006-12-01 10:40:55 +01:00
char Merge master.kernel.org:/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog 2006-12-01 16:47:26 -08:00
clocksource
connector
cpufreq
crypto
dio
dma
edac
eisa
fc4
firmware
hwmon
i2c Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2006-12-01 16:41:27 -08:00
ide Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
ieee1394
infiniband IB/ucm: Fix deadlock in cleanup 2006-11-29 15:33:10 -08:00
input Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2006-12-01 16:41:58 -08:00
isdn Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2006-12-01 16:41:58 -08:00
leds
macintosh
mca
md
media Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2006-12-01 16:41:58 -08:00
message Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2006-12-01 16:41:27 -08:00
mfd
misc
mmc Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6 2006-12-01 16:41:07 -08:00
mtd Fix typos in doc and comments 2006-11-30 05:32:19 +01:00
net Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2006-12-01 16:41:58 -08:00
nubus
oprofile
parisc Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
parport
pci Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2006-12-01 16:41:27 -08:00
pcmcia
pnp
rapidio
rtc
s390 Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
sbus
scsi Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
serial
sh
sn
spi Fix misc Kconfig typos 2006-11-30 05:22:59 +01:00
tc
telephony
usb Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6 2006-12-01 16:41:58 -08:00
video Driver core: convert fb code to use struct device 2006-12-01 14:52:00 -08:00
w1
zorro
Kconfig
Makefile