Some devices have several controllers; need add the index info to
device slot name host->slot_desc[]
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Both of these drivers work well (although some hardware still has
its problems) and are not in the "alpha" quality that EXPERIMENTAL
suggests.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
As pci config space is reinitialised on a suspend/resume cycle, the
disabler needs to work its magic at resume time. For symmetry this
change also explicitly enables the controller at suspend time but
it's not strictly necessary.
Signed-off-by: Philipl Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Move the tps65010 header file from the OMAP arch directory to the
more generic <linux/i2c/...> directory, and remove the spurious
dependency of this driver on OMAP.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patchis to add the first mmc controller support for pxa3xx.
It's valid for pxa3[0|1|2]0.
On zylonite, the first controller supports two slots, this patch
only support the first one right now.
Signed-off-by: Bridge Wu <bridge.wu@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch is to move pxamci DMA specific code to corresponding
platform layer because using DRCMRRXMMC/DRCMRTXMMC in pxamci.c makes
the driver code dedicated to platform which is not extensible.
It is applicable to all pxa platforms.
Signed-off-by: Bridge Wu <bridge.wu@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
pxa3[0|1]0 mmc controller can support 26MHz clock mode, they support
SD spec 1.1 and MMC spec 4.0 which specify high speed mode. So host
caps will include MMC_CAP_MMC_HIGHSPEED and MMC_CAP_SD_HIGHSPEED for
pxa3[0|1]0.
This patch is to add 26MHz support for them. pxa host clock will be
set to 26MHz mode when the card supported max clock rate is higher
than or equal to 26MHz.
Signed-off-by: Bridge Wu <bridge.wu@marvell.com>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The JMicron JMB38x chip doesn't support transfers that aren't 32-bit
aligned (both size and start address). It also doesn't like switching
between PIO and DMA mode, so it needs to be reset after each request.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some controllers have been designed on the assumption that all transfers
will be 32-bit aligned, both in start address and in size. This is not a
guarantee the SDHCI specification provides and not one we can provide.
Revert back to PIO for individual requests in order to work around the
hardware bug.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Given the patch which simplifies the spi_sync calling convention, this one
updates the callers of that routine which tried using it according to the
previous specification. (Most didn't.)
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is possible to handle arbitrary block sizes with tifm card reader by
conditionally switching to PIO in case such block has to be delivered. At
the beginning of each request, DMA is either disabled (non-power-of-2 block
size) or set to load time user preference.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Fix:
WARNING: at arch/arm/mach-pxa/clock.c:69 clk_disable()
[<c002d7c8>] (dump_stack+0x0/0x14) from [<c00334f4>] (clk_disable+0x34/0xa0)
[<c00334c0>] (clk_disable+0x0/0xa0) from [<c028a43c>] (pxamci_set_ios+0x74/0xf0)
[<c028a3c8>] (pxamci_set_ios+0x0/0xf0) from [<c0281548>] (mmc_power_off+0x90/0x9c)
[<c02814b8>] (mmc_power_off+0x0/0x9c) from [<c0281a30>] (mmc_start_host+0x18/0x28)
[<c0281a18>] (mmc_start_host+0x0/0x28) from [<c02825a0>] (mmc_add_host+0xe8/0x104)
[<c02824b8>] (mmc_add_host+0x0/0x104) from [<c028a7d0>] (pxamci_probe+0x24c/0x2f4)
[<c028a584>] (pxamci_probe+0x0/0x2f4) from [<c01e5948>] (platform_drv_probe+0x20/0x24)
...
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
#include <scatterlist/scatterlist.h>
is an odd thing to do...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch 49dce689ad changed the sysfs data
structures for SPI in a way which broke the MMC-over-SPI host driver.
This patch fixes that regression by changing the scheme used to keep
from knowingly trying to use a shared bus segment, and updates the
adjacent comments slightly to better explain the issue.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Do a full scan of the directory to try and be a bit more proactive,
instead of waiting for things to break.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Commits
58b053e4ce ("Update arch/ to use sg helpers")
45711f1af6 ("[SG] Update drivers to use sg helpers")
fa05f1286b ("Update net/ to use sg helpers")
converted many files to use the scatter gather helpers without ensuring
that the necessary headerfile <linux/scatterlist> is included. This
happened to work for ia64, powerpc, sparc64 and x86 because they
happened to drag in that file via their <asm/dma-mapping.h>.
On most of the others this probably broke.
Instead of increasing the header file spider web I choose to include
<linux/scatterlist.h> directly into the affectes files.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A small MMC driver cleanup.
Use the defined AT91_MCI_ERRORS in at91_mci_completed_command() instead
of specifying all the error bits individually.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
AFAICS, fallout from repacing include of blkdev.h with include of bio.h.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the SPI framework and drivers stop using class_device. Update docs
accordingly ... highlighting just which sysfs paths should be
"safe"/stable.
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (95 commits)
[ARM] 4578/1: CM-x270: PCMCIA support
[ARM] 4577/1: ITE 8152 PCI bridge support
[ARM] 4576/1: CM-X270 machine support
[ARM] pxa: Avoid pxa_gpio_mode() in gpio_direction_{in,out}put()
[ARM] pxa: move pxa_set_mode() from pxa2xx_mainstone.c to mainstone.c
[ARM] pxa: move pxa_set_mode() from pxa2xx_lubbock.c to lubbock.c
[ARM] pxa: Make cpu_is_pxaXXX dependent on configuration symbols
[ARM] pxa: PXA3xx base support
[NET] smc91x: fix PXA DMA support code
[SERIAL] Fix console initialisation ordering
[ARM] pxa: tidy up arch/arm/mach-pxa/Makefile
[ARM] Update arch/arm/Kconfig for drivers/Kconfig changes
[ARM] 4600/1: fix kernel build failure with build-id-supporting binutils
[ARM] 4599/1: Preserve ATAG list for use with kexec (2.6.23)
[ARM] Rename consistent_sync() as dma_cache_maint()
[ARM] 4572/1: ep93xx: add cirrus logic edb9307 support
[ARM] 4596/1: S3C2412: Correct IRQs for SDI+CF and add decoding support
[ARM] 4595/1: ns9xxx: define registers as void __iomem * instead of volatile u32
[ARM] 4594/1: ns9xxx: use the new gpio functions
[ARM] 4593/1: ns9xxx: implement generic clockevents
...
Make sure the mmc_spi driver can build without CONFIG_BLOCK.
Issue noted by "Avuton Olrich" <avuton@gmail.com> and randconfig.
While that won't be a common configuration, sometimes embedded
boards use SDIO to interface WLAN or Bluetooth chips (vs some
parallel interface), and don't provide an MMC/SD socket for use
with flash memory cards.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using weight32() to determine if a value is a power of 2 is a rather
heavi weight solution. The classic idiom is (x & (x - 1)) == 0, but
the kernel already provide a is_power_of_2 function for it.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The PXA has two transmit FIFOes, each32 byte deep. when one FIFO is
full and the other one has been transmitted, they are automatically
swapped and DMA is triggered for another 32 byte burst. However, when
there is less than 32 bytes left to send, the FIFO swap has to be done
manually. This is required for some SDIO transfers which are not
required to be multiples of 32 bytes.
A DMA completion interrupt is set for each descriptor which length isn't
a multiple of 32 in order to force the FIFO swap. While at it, the DMA
interrupt handler has been made a bit more resilient against errors.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The forcedma and nodma module parameters can be replaced with the quirks
parameter, so remove the redundancy.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some controllers like ENE712 can't work properly with DMA mode,
add this quirk to force these kinds of HW work with PIO mode
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Many host controllers don't fully follow the PCI spec to claim
whether they support DMA in PCI class register. Leave the driver
to judge it from the Capability register, quirks and module parameter
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Thanks to Matt Domsch and Rezwanul Kabir at Dell, we know how to disable the
MMC controller on the multi-function Ricoh R5C832. The MMC controller needs
to be disabled or it will steal MMC cards from the SD controller where they
would otherwise be supported by the Linux SDHCI driver.
Signed-off-by: Philipl Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Again, only available from PXA27x.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
From PXA27x, it is possible to do 4-bit data transfers.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
From PXA27x, it is possible to do 2048-byte block transfers.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Pending interrupts should be determined from both I_REG and I_MASK
registers.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The patch enables to define MMC host get_ro() method through platform data.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This is the latest version of the MMC-over-SPI support. It works
on 2.6.23-rc2 plus git-mmc (from rc1-mm2), along with the preceding
patches which teach the rest of the MMC stack about SPI.
The main issue of note is that sometimes cards need to be power cycled
to recover after certain faults. Also, it may sometimes be necessary
to disable CRCs. ("modprobe mmc_core use_spi_crc=n")
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: mikael.starvik@axis.com,
Cc: Hans-Peter Nilsson <hp@axis.com>
Cc: Jan Nikitenko <jan.nikitenko@gmail.com>
Cc: Mike Lavender <mike@steroidmicros.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This kind of transfer is not supported, so don't advertise it and make it
fail early.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The MMC_DATA_MULTI flag never had a proper definition of what it
means, so remove it and let the drivers check the block count in
the request.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch fixes a bug in AT91 mmc host driver, that enables the wakeup
from suspend on card detection pin even if the card detect pin is not
available (==0). If not card detection pin is defined, IRQ0 == FIQ gets
enabled and if some activity is present on that pin, the system gets a
FIQ request, that causes a crash.
Signed-off-by: Anti Sullin <anti.sullin@artecdesign.ee>
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
It is fully legal for a controller to start issuing data related
interrupts before it has signalled that the command has completed.
Make sure the driver actually can handle this.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some SDHC cards report an invalid maximum block size, in these cases
assume they support block sizes up to 512 bytes instead of returning
an error.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The block count register shouldn't be trusted for single block transfers,
so avoid using it completely when calculating transferred bytes.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some cleanup with whitespace/tab at the end of lines.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch fixes the following section mismatch warnings
...
WARNING: vmlinux.o(.init.text+0x29d40): Section mismatch: reference to .exit.text:wbsd_release_resources (between 'wbsd_init' and 'wbsd_probe')
WARNING: vmlinux.o(.init.text+0x29d49): Section mismatch: reference to .exit.text:wbsd_free_mmc (between 'wbsd_init' and 'wbsd_probe')
WARNING: vmlinux.o(.init.text+0x29f28): Section mismatch: reference to .exit.text:wbsd_free_mmc (between 'wbsd_init' and 'wbsd_probe')
...
Signed-off-by: Gabriel Craciunescu <nix.or.die@googlemail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Added its pci_id and implemented a quirk for it because this
controller needs to reset cmd and data when setting ios.
Signed-off-by: Leandro Dorileo <dorileo@ossystems.com.br>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Some controllers signal "command complete" even on failures (which
they are allowed to do according to the spec). Make sure we check
the error bits first so we don't get any false positives.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The controller has a bit indicating that one of the higher bits (the
error bits) are set. A previous bug caused this bit to be masked, but
since that bug has been fixed we have to clear it explicictly.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This piece of code enable the system to be wake-up by a card insertion or removal.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (50 commits)
[ARM] sa1100: remove boot time RTC initialisation
[ARM] sa1100: stop doing our own rtc management over suspend
[ARM] 4474/1: Do not check the PSR_F_BIT in valid_user_regs
[ARM] 4473/2: Take the HWCAP definitions out of the elf.h file
[ARM] pxa: move platform devices to separate header file
[ARM] pxa: move device registration into CPU-specific file
[ARM] pxa: remove boot time RTC initialisation
[ARM] pxa: stop doing our own rtc management over suspend
[ARM] 4451/1: pxa: make dma.c generic and remove cpu specific dma code
[ARM] 4450/1: pxa: add pxa25x_init_irq() and pxa27x_init_irq()
[ARM] 4440/1: PXA: enable the checking of ICIP2 for IRQs
[ARM] 4438/1: PXA: remove #ifdef .. #endif from pxa_gpio_demux_handler()
[ARM] 4437/1: PXA: move the GPIO IRQ initialization code to pxa_init_irq_gpio()
[ARM] 4436/1: PXA: move low IRQ initialization code to pxa_init_irq_low()
[ARM] 4435/1: PXA: remove PXA_INTERNAL_IRQS
[ARM] 4434/1: PXA: remove PXA_IRQ_SKIP
[ARM] pxa: Fix PXA27x suspend type validation, remove pxa_pm_prepare()
[ARM] pxa: move pm_ops structure into CPU specific files
[ARM] pxa: introduce cpu_is_pxaXXX macros
[ARM] pxa: remove MMC register defines from pxa-regs.h
...
pxamci.h redefines the MMC registers differently so they can be used
with ioremap. Remove the incompatible definitions from pxa-regs.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fixes hanging using multi block operations (seen during CMD25).
Follows closely the datasheet flowcharts.
This piece of code handles better big file writing. I had to take care
of the notbusy signal during write (at91_mci_handle_cmdrdy function) and
to rearrange the AT91_MCI_ENDRX and AT91_MCI_RXBUFF flag usage.
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Typo fix in at91_mci driver : standardized the typo
(at91_mci everywhere)
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Whenever a power interrupt is signaled it is also reported as an unexpected
one. All other unexpected interrupts get lost. Cause is a not inversed
bitmask to remove power interrupts from the status.
Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
ENE has a very weird design where an SDHCI device (0805) is presented
on the PCI bus, but that device is non-functional, and the real device
is hidden as a more generic device.
Signed-off-by: Milko Krachounov <milko@3mhz.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Ignoring OMAP_MMC_STAT_CARD_ERR, treating it as if the command
completed correctly.
Signed-off-by: Ragner Magalhaes <ragner.magalhaes@indt.org.br>
Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar@indt.org.br>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Fix compilation error by removing command decoding from at91_mci.c driver.
Decoding commands in the host driver is the wrong way.
Signed-off-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
... and make it depend on the response flag instead of the command type.
Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
When the device hits certain memory boundaries, it signals an
interrupt and expects to be serviced. We don't need the feature
but we need to make sure the device doesn't stall.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch has changed command types check from data flags.
MMC_STOP_TRANSMISSION is never passed to au1xmmc_send_command().
SEND_STOP() is used for MMC_STOP_TRANSMISSION.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Change Kconfig objects from "menu, config" into "menuconfig" so
that the user can disable the whole feature without having to
enter the menu first.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Socket power must be fully controlled by adapter driver. This also prevents
unnecessary power-off of the socket when media driver is unloaded, yet
media remains in the socket.
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Move divisor calculation into a separate function and re-arrange the
init order to make MMC_POWER_ON work.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
As discussed earlier on LKML:
http://lkml.org/lkml/2006/5/4/44
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch add a missing '\n' at the end of the 'cover is open' string
in mmc_omap_switch_handler().
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch makes the needlessly global tifm_sd_set_dma_data() static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Fix handling of low voltage MMC cards.
The latest MMC and SD specs both agree that support for
low-voltage operations is indicated by bit 7 in the OCR.
The MMC spec states that the low voltage range is
1.65-1.95V while the SD spec leaves the actual voltage
range undefined - meaning that there is still no such
thing as a low voltage SD card.
However, an old Sandisk spec implied that bits 7.0
represented voltages below 2.0V in 1V or 0.5V increments,
and the code was accordingly written with that expectation.
This confusion meant that host drivers attempting to support
the typical low voltage (1.8V) would set the wrong bits in
the host OCR mask (usually bits 5 and/or 6) resulting in the
the low voltage mode never being used.
This change corrects the low voltage range and adds sanity
checks on the reserved bits (0-6) and for SD cards that
claim to support low-voltage operations.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Consolidate the list of available voltages.
Up until now, a separate set of defines has been
used for host->vdd than that used for the OCR
voltage mask values. Having two sets of defines
allows them to get out of sync and the current
sets are already inconsistent with one claiming
to describe ranges and the other specific voltages.
Only the SDHCI driver uses the host->vdd defines and
it is easily fixed to use the OCR defines.
Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Move the check for supported data opcodes to the beginning of the
request function to avoid wedging the card.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Feng Tang