linux/drivers
Rajat Jain cdcefe6bd9 mmc: sdhci-pci: Try "cd" for card-detect lookup before using NULL
Problem:

The card detect IRQ does not work with modern BIOS (that want
to use _DSD to provide the card detect GPIO to the driver).

Details:

The mmc core provides the mmc_gpiod_request_cd() API to let host drivers
request the gpio descriptor for the "card detect" pin.
This pin is specified in the ACPI for the SDHC device:

 * Either as a resource using _CRS. This is a method used by legacy BIOS.
   (The driver needs to tell which resource index).

 * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally
   points to an entry in _CRS). This way, the driver can lookup using a
   string. This is what modern BIOS prefer to use.

This API finally results in a call to the following code:

struct gpio_desc *acpi_find_gpio(..., const char *con_id,...)
{
...
   /* Lookup gpio (using "<con_id>-gpio") in the _DSD */
...
   if (!acpi_can_fallback_to_crs(adev, con_id))
          return ERR_PTR(-ENOENT);
...
   /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */
...
}

Note that this means that if the ACPI has _DSD properties, the kernel
will never use _CRS for the lookup (Because acpi_can_fallback_to_crs()
will always be false for any device hat has _DSD entries).

The SDHCI driver is thus currently broken on a modern BIOS, even if
BIOS provides both _CRS (for index based lookup) and _DSD entries (for
string based lookup). Ironically, none of these will be used for the
lookup currently because:

* Since the con_id is NULL, acpi_find_gpio() does not find a matching
  entry in DSDT. (The _DSDT entry has the property name = "cd-gpios")

* Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs()
  returns false (because device properties have been populated from
  _DSD), thus the _CRS is never used for the lookup.

Fix:

Try "cd" for lookup in the _DSD before falling back to using NULL so
as to try looking up in the _CRS.

I've tested this patch successfully with both Legacy BIOS (that
provide only _CRS method) as well as modern BIOS (that provide both
_CRS and _DSD). Also the use of "cd" appears to be fairly consistent
across other users of this API (other MMC host controller drivers).

Link: https://lkml.org/lkml/2018/9/25/1113
Signed-off-by: Rajat Jain <rajatja@google.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: f10e4bf663 ("gpio: acpi: Even more tighten up ACPI GPIO lookups")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-11-19 12:01:18 +01:00
..
accessibility
acpi acpi/nfit, x86/mce: Validate a MCE's address before using it 2018-11-06 19:13:26 +01:00
amba
android
ata sata_rcar: convert to SPDX identifiers 2018-11-08 06:32:16 -07:00
atm atm: zatm: Fix empty body Clang warnings 2018-10-18 15:39:10 -07:00
auxdisplay The Compiler Attributes series 2018-11-01 18:34:46 -07:00
base mm/memory_hotplug: fix online/offline_pages called w.o. mem_hotplug_lock 2018-10-31 08:54:17 -07:00
bcma
block xen: fixes for 4.20-rc2 2018-11-10 08:58:48 -06:00
bluetooth Merge branch 'work.tty-ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-10-24 14:43:41 +01:00
bus ARM: SoC driver updates for 4.17 2018-10-29 15:16:01 -07:00
cdrom gdrom: fix mistake in assignment of error 2018-10-25 11:17:40 -06:00
char RTC for 4.20 2018-10-27 09:24:24 -07:00
clk clk: qcom: gcc: Fix board clock node name 2018-11-09 14:13:55 -08:00
clocksource Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-11-11 16:41:50 -06:00
connector
cpufreq cpufreq: remove unused arm_big_little_dt driver 2018-10-25 18:39:02 +02:00
cpuidle More power management updates for 4.20-rc1 2018-10-30 09:08:07 -07:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-10-25 16:43:35 -07:00
dax
dca
devfreq
dio
dma pci-v4.20-changes 2018-10-25 06:50:48 -07:00
dma-buf
edac * skx_edac: Address translation for NVDIMMs (Tony Luck and Qiuxu Zhuo) 2018-11-02 11:17:22 -07:00
eisa
extcon
firewire
firmware Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-11-03 18:25:17 -07:00
fmc
fpga fpga: add devm_fpga_region_create 2018-10-16 11:13:50 +02:00
fsi iov_iter: Separate type from direction and use accessor functions 2018-10-24 00:41:07 +01:00
gnss
gpio pci-v4.20-changes 2018-10-25 06:50:48 -07:00
gpu drm: i915, amdgpu, sun4i, exynos and etnaviv fixes 2018-11-10 13:29:47 -06:00
hid HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled 2018-11-06 13:57:42 +01:00
hsi
hv hv_balloon: Replace spin_is_locked() with lockdep 2018-10-15 20:54:17 +02:00
hwmon hwmon: (ibmpowernv) Remove bogus __init annotations 2018-11-04 15:55:12 -08:00
hwspinlock
hwtracing stm class: Use memcat_p() 2018-10-11 12:12:55 +02:00
i2c i2c: nvidia-gpu: make pm_ops static 2018-11-09 17:56:44 +01:00
ide
idle Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 13:32:18 +01:00
iio Staging/IIO patches for 4.20-rc1 2018-10-29 10:38:10 -07:00
infiniband Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks" 2018-10-26 16:25:19 -07:00
input Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax 2018-10-28 11:35:40 -07:00
iommu mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
ipack
irqchip irqchip/irq-mvebu-sei: Fix a NULL vs IS_ERR() bug in probe function 2018-11-01 12:38:48 +01:00
isdn Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-01 19:58:52 -07:00
leds LED fixes for 4.20-rc2 2018-11-08 17:49:04 -06:00
lightnvm
macintosh memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
mailbox - Convert print users to use the %pOFn format specifier 2018-10-29 10:30:44 -07:00
mcb
md for-linus-20181102 2018-11-02 11:25:48 -07:00
media media updates for v4.20-rc1 2018-10-31 10:53:29 -07:00
memory
memstick
message
mfd chrome-platform for v4.20 2018-10-31 16:47:55 -07:00
misc Merge branch 'work.afs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-11-01 19:58:52 -07:00
mmc mmc: sdhci-pci: Try "cd" for card-detect lookup before using NULL 2018-11-19 12:01:18 +01:00
mtd mtd: sa1100: avoid VLA in sa1100_setup_mtd 2018-11-06 10:38:17 +01:00
mux This is the bulk of GPIO changes for the v4.20 series: 2018-10-23 08:45:05 +01:00
net net: dsa: mv88e6xxx: Fix clearing of stats counters 2018-11-11 10:19:10 -08:00
nfc NFC: nfcmrvl_uart: fix OF child-node lookup 2018-10-23 13:28:53 -05:00
ntb ntb: idt: Alter the driver info comments 2018-11-01 10:33:12 -04:00
nubus
nvdimm libnvdimm for 4.20 2018-10-25 06:31:56 -07:00
nvme for-linus-20181109 2018-11-09 16:31:51 -06:00
nvmem nvmem: hide unused nvmem_find_cell_by_index function 2018-10-15 15:56:15 +02:00
of Devicetree fixes for 4.20-rc: 2018-11-09 16:41:58 -06:00
opp
oprofile
parisc parisc: Add alternative coding infrastructure 2018-10-17 17:22:26 +02:00
parport
pci Merge branch 'xarray' of git://git.infradead.org/users/willy/linux-dax 2018-10-28 11:35:40 -07:00
pcmcia powerpc updates for 4.20 2018-10-26 14:36:21 -07:00
perf arm64 updates for 4.20: 2018-10-22 17:30:06 +01:00
phy USB/PHY patches for 4.20-rc1 2018-10-26 08:14:13 -07:00
pinctrl This is the bulk of GPIO changes for the v4.20 series: 2018-10-23 08:45:05 +01:00
platform platform-drivers-x86 for v4.20-1 2018-11-01 08:42:21 -07:00
pnp
power Devicetree updates for 4.20: 2018-10-26 12:09:58 -07:00
powercap Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 13:32:18 +01:00
pps
ps3
ptp ptp: drop redundant kasprintf() to create worker name 2018-10-28 19:20:06 -07:00
pwm pwm: lpss: Only set update bit if we are actually changing the settings 2018-10-16 13:16:15 +02:00
rapidio
ras
regulator regulator: Regulator updates for next release 2018-10-23 01:54:44 +01:00
remoteproc remoteproc: qcom: q6v5-mss: Register segments/dumpfn for coredump 2018-10-19 12:54:03 -07:00
reset ARM: SoC driver updates for 4.17 2018-10-29 15:16:01 -07:00
rpmsg
rtc rtc: sc27xx: Always read normal alarm when registering RTC device 2018-10-25 02:35:42 +02:00
s390 s390/qeth: report 25Gbit link speed 2018-11-03 10:44:06 -07:00
sbus
scsi Kbuild updates for v4.20 (2nd) 2018-11-03 10:47:33 -07:00
sfi mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
sh
siox
slimbus
sn
soc soc: ti: QMSS: Fix usage of irq_set_affinity_hint 2018-11-02 11:22:09 -07:00
soundwire
spi - New Drivers 2018-10-25 06:19:15 -07:00
spmi
ssb
staging media updates for v4.20-rc1 2018-10-31 10:53:29 -07:00
target SCSI misc on 20181102 2018-11-03 10:34:03 -07:00
tc TC: Set DMA masks for devices 2018-10-11 09:16:44 -07:00
tee
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2018-10-31 11:28:12 -07:00
thunderbolt
tty TTY/Serial fixes for 4.20-rc2 2018-11-10 13:32:14 -06:00
uio
usb usb: typec: ucsi: add support for Cypress CCGx 2018-11-09 18:49:59 +01:00
uwb
vfio VFIO updates for v4.20 2018-10-31 11:01:38 -07:00
vhost virtio, vhost: fixes, tweaks 2018-11-01 14:42:49 -07:00
video fbdev changes for v4.20: 2018-10-31 11:41:37 -07:00
virt
virtio virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON 2018-10-24 20:57:55 -04:00
visorbus
vlynq
vme
w1 w1: IAD Register is yet readable trough iad sys file. Fix snprintf (%u for unsigned, count for max size). 2018-10-15 20:50:32 +02:00
watchdog watchdog: ts4800: release syscon device node in ts4800_wdt_probe() 2018-10-22 10:16:28 +02:00
xen xen: fixes for 4.20-rc2 2018-11-10 08:58:48 -06:00
zorro
Kconfig
Makefile