This patch adds adma_table_cnt member to struct sdhci_host to give more
flexibility to drivers to control the ADMA table count.
Default value of adma_table_cnt is set to (SDHCI_MAX_SEGS * 2 + 1).
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Allow SDHCI drivers to hook code before and after sdhci_request() by
making it externally visible.
Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch is to add tuning error codes to
judge tuning state
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Export sdhci tuning function symbols which are used by other SD Host
controller driver modules.
Signed-off-by: ernest.zhang <ernest.zhang@bayhubtech.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
For eMMC devices it is valid to only support 1.8V signaling. When
vqmmc is set to a fixed 1.8V regulator the stack tries to set 3.3V
initially and prints the following warning:
mmc1: Switching to 3.3V signalling voltage failed
Clear the MMC_SIGNAL_VOLTAGE_330 flag in case 3.3V is signaling is
not available. This prevents the stack from even trying to use
3.3V signaling and avoids the above warning.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
sdhci has a 10 second timeout to catch devices that stop responding.
In the case of quirk SDHCI_QUIRK2_DISABLE_HW_TIMEOUT, instead of
programming 10 second arbitrary value, calculate the total time it would
take for the entire transfer to happen and program the timeout value
accordingly.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Factor out the target_timeout calculation so it can be re-used.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Add quirk to disable HW timeout if the requested timeout is more than the
maximum obtainable timeout.
Also, if the quirk is set and ->get_max_timeout_count() is not implemented,
max_busy_timeout is set to zero.
Based-on-patch-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The SDHCI controller in a SoC might support HS200/HS400 (indicated
using mmc-hs200-1_8v/mmc-hs400-1_8v dt property), but if the board is
modeled such that the IO lines are not connected to 1.8v then
HS200/HS400 cannot be supported. Disable HS200/HS400 if the board
does not have 1.8v connected to the IO lines. Also Disable DDR/UHS in 1.8v
if the IO lines are not connected to 1.8v.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Do not enable wakeup for SDIO card interrupt unless the SDIO function
driver has requested it which is indicated by mmc_card_wake_sdio_irq().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Do not unnecessarily enable card detect wakeup in the cases that the card
is not removable or a GPIO is used for card detect.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The bounce buffer is gone from the MMC core, and now we found out
that there are some (crippled) i.MX boards out there that have broken
ADMA (cannot do scatter-gather), and also broken PIO so they must
use SDMA. Closer examination shows a less significant slowdown
also on SDMA-only capable Laptop hosts.
SDMA sets down the number of segments to one, so that each segment
gets turned into a singular request that ping-pongs to the block
layer before the next request/segment is issued.
Apparently it happens a lot that the block layer send requests
that include a lot of physically discontiguous segments. My guess
is that this phenomenon is coming from the file system.
These devices that cannot handle scatterlists in hardware can see
major benefits from a DMA-contiguous bounce buffer.
This patch accumulates those fragmented scatterlists in a physically
contiguous bounce buffer so that we can issue bigger DMA data chunks
to/from the card.
When tested with a PCI-integrated host (1217:8221) that
only supports SDMA:
0b:00.0 SD Host controller: O2 Micro, Inc. OZ600FJ0/OZ900FJ0/OZ600FJS
SD/MMC Card Reader Controller (rev 05)
This patch gave ~1Mbyte/s improved throughput on large reads and
writes when testing using iozone than without the patch.
dmesg:
sdhci-pci 0000:0b:00.0: SDHCI controller found [1217:8221] (rev 5)
mmc0 bounce up to 128 segments into one, max segment size 65536 bytes
mmc0: SDHCI controller on PCI [0000:0b:00.0] using DMA
On the i.MX SDHCI controllers on the crippled i.MX 25 and i.MX 35
the patch restores the performance to what it was before we removed
the bounce buffers.
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Benoît Thébaudeau <benoit@wsystem.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Benjamin Beckmeyer <beckmeyer.b@rittal.de>
Cc: stable@vger.kernel.org # v4.14+
Fixes: de3ee99b09 ("mmc: Delete bounce buffer handling")
Tested-by: Benjamin Beckmeyer <beckmeyer.b@rittal.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
In preparation for adding more conditions for whether IRQ wakeup is
enabled, rework sdhci_enable_irq_wakeups() so that needed bits are added
instead of adding them all and then removing the unneeded bits.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Now that sdhci_enable_irq_wakeups() is a local function, change it to
return whether the IRQ wakeup was successfully enabled. This is in
preparation for adding more conditions for whether IRQ wakeup is enabled.
Note it is assumed, for SDHCI devices, that suspend is more important than
wakeup, so we continue to suspend regardless.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Now that it is not being used by any drivers, stop exporting it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
On Intel Edison the Broadcom Wi-Fi card, which is connected to SDIO,
requires 2.0v, while the host, according to Intel Merrifield TRM,
supports 1.8v supply only.
The card announces itself as
mmc2: new ultra high speed DDR50 SDIO card at address 0001
Introduce a custom OCR mask for SDIO host controller on Intel Merrifield
and add a special case to sdhci_set_power_noreg() to override 2.0v supply
by enforcing 1.8v power choice.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The commit de3ee99b09 ("mmc: Delete bounce buffer handling") deletes the
bounce buffer handling, but also causes the max_req_size for sdhci to be
increased, in case when max_segs == 1. This causes errors for sdhci-pci
Ricoh variant, about the swiotlb buffer to become full.
Fix the issue, by taking IO_TLB_SEGSIZE and IO_TLB_SHIFT into account when
deciding the max_req_size for sdhci.
Reported-by: Jiri Slaby <jslaby@suse.cz>
Fixes: de3ee99b09 ("mmc: Delete bounce buffer handling")
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Bruce Chang <brucechang@via.com.tw>
Cc: Harald Welte <HaraldWelte@viatech.com>
Cc: Tony Olech <tony.olech@elandigitalsystems.com>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Allen <allen.lkml@gmail.com>
Cc: linux-mmc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-omap@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Bail out everytime when mmc_regulator_get_supply() returns an errno, not
only when probing gets deferred. This is currently a no-op, because this
function only returns -EPROBE_DEFER or 0 right now. But if it will throw
another error somewhen, it will be for a reason. (This still doesn't change
that getting regulators is optional, so 0 can still mean no regulators
found). So, let us a) be future proof and b) have driver code which is
easier to understand.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
TI's implementation of sdhci controller used in DRA7 SoC's has
CRC in responses with length 136 bits. Add quirk to indicate
the controller has CRC in MMC_RSP_136. If this quirk is
set sdhci library shouldn't shift the response present in
SDHCI_RESPONSE register.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Read each register only once and move the code to a separate function so
that it is not jammed against the 80 column margin.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
SD controller with SDHCI_QUIRK_NO_HISPD_BIT quirk probably
use high speed enable bit for other purpose. So this bit
shouldn't be changed for high speed enabling for this type of
SD controller.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Hosts supporting 8-bit bus are marked accordingly. If MMC_CAP_8_BIT_DATA
is not among host capabilities, 8BITBUS bit will never be set and it
is not cleared in case some non-SDHCI3 host uses it for something else.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds sdma_boundary member to struct sdhci_host to give more
flexibility to drivers to control the sdma boundary buffer value and
also to fix issue on some sdhci controllers which are broken when
HOST SDMA Buffer Boundary is programmed in Block Size Register (0x04)
when using ADMA. Qualcomm sdhci controller is one of such type, writing
to this bits is un-supported.
Default value of sdma_boundary is set to SDHCI_DEFAULT_BOUNDARY_ARG.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
One issue was found on a removable high speed sd card with
runtime pm enabled.
When SD card is unplugged, it keep printing "Switching to 3.3V
signalling voltage failed".
And found below sequence triggers the error.
mmc_rescan
-> mmc_sd_detect
-> mmc_power_off -- mmc->ios.vdd is updated to 0.
-> mmc_claim_host
-> sdhci_runtime_resume_host
-> sdhci_start_signal_voltage_switch
-> mmc_regulator_set_vqmmc
-> mmc_ocrbitnum_to_vdd
When mmc_ocrbitnum_to_vdd is called, the mmc->ios.vdd is 0, so it
always return -EINVAL. The signal switch will always fail and
print out warning.
Ignore restoring the I/O state when runtime resume if MMC_POWER_OFF.
Signed-off-by: Zhoujie Wu <zjwu@marvell.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
sdhci uses CONFIG_MMC_DEBUG for showing ADMA descriptor
when occurring ADMA error. And it's also used to dump the
registers whenever calling sdhci_add_host.
On one hand, I don't see any burden to always print the state
ADMA descriptor as it's rare and will help folks better understand
what was happening when seeing ADMA error.
On the other, folks may be interested in checking some registers
at probe time. So we remove the sdhci_dumpregs from __sdhci_add_host
and print some really useful registers in sdhci_setup_host.
Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The delay between tuning commands for SD cards is not part of the
specification. A driver that needs it probably needs it for eMMC
too, whereas most drivers would probably like to set it to 0. Make
it a host member (host->tuning_delay) that defaults to the existing
behaviour. Drivers can set it to zero to eliminate the delay, or
set it to a positive value to always have a delay.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Export sdhci_start_signal_voltage_switch() from sdhci.c.
Thus vendor sdhci driver can implement its own signal voltage
switch routine.
Signed-off-by: Hu Ziji <huziji@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Export sdhci_set_ios() in sdhci.c.
Thus vendor sdhci driver can implement its own set_ios() routine.
Signed-off-by: Hu Ziji <huziji@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Currently the get_timeout_clock callback doesn't clearly
have a statement that it needs the variant drivers to return
the timeout clock rate in kHz if the SDHCI_TIMEOUT_CLK_UNIT
isn't present, otherwise the variant drivers should return it
in MHz. It's also very likely that further variant drivers which
are going to use this callback will be confused by this situation.
Given the fact that moderm sdhci variant hosts are very prone to get
the timeout clock from common clock framework (actually the only three
users did that), it's more natural to return the value in Hz and we
make an explicit comment there. Then we put the unit conversion inside
the sdhci core. Thus will improve the code and prevent further misuses.
Reported-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Add an interrupt hook and helper functions for enabling, disabling and
delivering interrupts to a CQE.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Export sdhci_dumpregs so that it can be called by drivers.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Ensure all prints start with the mmc host name, and the text all lines up.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Ensure all debug prints start with the mmc host name.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Tuning execution is already synchronized with respect to other host
operations by upper layers "claiming" the host, which also takes care of
runtime pm. There can be no requests in progress. Retain the spin lock
usage only for ensuring that sending tuning commands is synchronized with
respect to the interrupt handler.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
The spin lock is not necessary in set_ios. Anything that is racing with
changes to the I/O state is already broken. The mmc core already provides
synchronization via "claiming" the host. So remove spin_lock and friends
from sdhci_set_ios and related callbacks.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Drivers can use the host operation directly, so remove this now unused
callback.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Devices might save and restore tuning values so that re-tuning might not be
needed after a pm transition. Let drivers decide by pushing the
mmc_retune_needed() logic down to them.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
The delay loops for reset and clock enable always take at least 1 ms
because they use mdelay(1). However they can take a lot less time e.g. less
than 50us. Use ktime and reduce the delay to 10 microseconds per loop.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
SDIO cards may need clock to send the card interrupt to the host.
On a cherrytrail tablet with a RTL8723BS wifi chip, without this patch
pinging the tablet results in:
PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=78.6 ms
64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1760 ms
64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=753 ms
64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=3.88 ms
64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=795 ms
64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1841 ms
64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=810 ms
64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1860 ms
64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=812 ms
64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=48.6 ms
Where as with this patch I get:
PING 192.168.1.14 (192.168.1.14) 56(84) bytes of data.
64 bytes from 192.168.1.14: icmp_seq=1 ttl=64 time=3.96 ms
64 bytes from 192.168.1.14: icmp_seq=2 ttl=64 time=1.97 ms
64 bytes from 192.168.1.14: icmp_seq=3 ttl=64 time=17.2 ms
64 bytes from 192.168.1.14: icmp_seq=4 ttl=64 time=2.46 ms
64 bytes from 192.168.1.14: icmp_seq=5 ttl=64 time=2.83 ms
64 bytes from 192.168.1.14: icmp_seq=6 ttl=64 time=1.40 ms
64 bytes from 192.168.1.14: icmp_seq=7 ttl=64 time=2.10 ms
64 bytes from 192.168.1.14: icmp_seq=8 ttl=64 time=1.40 ms
64 bytes from 192.168.1.14: icmp_seq=9 ttl=64 time=2.04 ms
64 bytes from 192.168.1.14: icmp_seq=10 ttl=64 time=1.40 ms
Cc: Dong Aisheng <b29396@freescale.com>
Cc: Ian W MORRISON <ianwmorrison@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Disabling interrupts for even a millisecond can cause problems for some
devices. That can happen when sdhci changes clock frequency because it
waits for the clock to become stable under a spin lock.
The spin lock is not necessary here. Anything that is racing with changes
to the I/O state is already broken. The mmc core already provides
synchronization via "claiming" the host.
Although the spin lock probably should be removed from the code paths that
lead to this point, such a patch would touch too much code to be suitable
for stable trees. Consequently, for this patch, just drop the spin lock
while waiting.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Clear SDHCI_HS400_TUNING flag after platform_execute_tuning
so that platform_execute_tuning may use it if needed.
Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>
Tested-by: Jeremy McNicoll <jeremymc@redhat.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
In the MMC subsystem, we see such initializers that only clears the
first member explicitly.
For example,
struct mmc_request mrq = {NULL};
sets the first member (.sbc) to NULL explicitly. However, this is
an unstable form because we may insert a non-pointer member at the
top of the struct mmc_request in the future. (if we do so, the
compiler will spit warnings.)
So, using a designated initializer is preferred coding style. The
expression above is equivalent to:
struct mmc_request mrq = { .sbc = NULL };
Of course, this does not express our intention. We want to fill
all struct members with zeros. Please note struct members are
implicitly zero-cleared unless otherwise specified in the initializer.
After all, the most reasonable (and stable) form is:
struct mmc_request mrq = {};
Do likewise for mmc_command, mmc_data as well.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
