Print the error code when the tuning command fails. This allows the
reason for the failure to be reported, which aids debugging.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Improve mmc_of_parse_voltage()'s return values so that drivers can tell
whether a voltage-range specification was present, and whether it has
been successfully parsed, or there was an error while parsing.
We return a negative errno when parsing fails, zero if no voltage-range
specification is present, or one if a voltage-range specification is
successfully parsed.
No users need modifying as no users check the return value.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Each time a driver such as sdhci-esdhc-imx is probed, we get a info
printk complaining that the DT voltage-ranges property has not been
specified.
However, the DT binding specifically says that the voltage-ranges
property is optional. That means we should not be complaining that
DT hasn't specified this property: by indicating that it's optional,
it is valid not to have the property in DT.
Silence the warning if the property is missing.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The bus width is sometimes the actual bus width, and sometimes indices
to different arrays encoding the bus width. In my debugging case "2"
could mean 8-bit as well as 4-bit, which was extremly confusing. Let's
use the human-readable actual bus width in all places.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
In linux/mmc/host.h, mmc_card_is_removable() is already defined.
There is no reason that it doesn't use.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The mmc workqueue is an ordered workqueue, allowing only one work to
execute per given time. As this workqueue is used for card detection, the
conseqeunce is that cards will be detected one by one waiting for each
other.
Moreover, most of the time spent during card initialization is waiting for
the card's internal firmware to be ready. From a CPU perspective this
typically means waiting for a completion variable to be kicked via an
IRQ-handler or waiting for a sleep timer to finish.
This behaviour of detecting/initializing cards is sub-optimal, especially
for SOCs having several controllers/cards.
Let's convert to use the system_freezable_wq for the mmc detect works.
This enables several works to be executed simultaneously and thus also
cards to be detected like so.
Tests on UX500, which holds two eMMC cards and an SD-card (actually also
an SDIO card, currently not detected), shows a significant improved
behaviour due to this change.
Before this change, both the eMMC cards waited for the SD card to be
initialized as its detect work entered the workqueue first. In some cases,
depending on the characteristic of the SD-card, they got delayed 1-1.5 s.
Additionally for the second eMMC, it needed to wait for the first eMMC to
be initialized which added another 120-190 ms.
Converting to the system_freezable_wq, removed these delays and made both
the eMMC cards available far earlier in the boot sequence.
Selecting the system_freezable_wq, in favour of for example the system_wq,
is because we need card detection mechanism to be disabled once userspace
are frozen during system PM. Currently the mmc core deal with this via PM
notifiers, but following patches may utilize the behaviour of the
system_freezable_wq, to simplify the use of the PM notifiers.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Alan Cooper <alcooperx@gmail.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
This patch introduce a new MMC_CAP2_NO_SDIO cap used to tell the mmc
core to not send SDIO specific commands.
Signed-off-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Turn the informative message about no vmmc/vqmmc regulator found in
debug one. There is no need to indicate that something optional is
missing. Moreover, it can bring confusion, people who doesn't know
it is optional may consider these messages as warnings or errors.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
_mmc_detect_card_removed() validates that the card is removable, but when
being called via the bus_ops ->detect() callbacks, the validation is
redundant as it's already done in mmc_rescan().
Move the validation of a removable card to the mmc_detect_card_removed()
API, which is where it's applicable, to allow the blk error recovery path
to get the response a bit earlier.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Instead of checking for "#ifdef" directly in the code, let's invent a pair
of mmc core functions to deal with register/unregister the MMC PM notifier
block. Implement stubs for these functions when CONFIG_PM_SLEEP is unset,
as in that case the PM notifiers isn't used.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
As mmc_claim_host() invokes pm_runtime_get_sync() for the mmc host device,
it's important that the host is kept claimed for *all* accesses to it via
the host_ops callbacks.
In mmc_rescan(), the ->card_event() and the ->get_cd() callback are being
invoked without claiming the host, let's fix this.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The ->card_event() callback may be called when re-scan is disabled and for
non-removable cards, which both cases are unnecessary.
Instead let's move the call later in mmc_rescan() where these constraints
have been validated.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This adds logic to the MMC core to set VQMMC. This is expected to be
called by MMC drivers like dw_mmc as part of (or instead of) their
start_signal_voltage_switch() callback.
A few notes:
* When setting the signal voltage to 3.3V we do our best to make VQMMC
and VMMC match. It's been reported that this makes some old cards
happy since they were tested back in the day before UHS when VQMMC
and VMMC were provided by the same regulator. A nice side effect of
this is that we don't end up on the hairy edge of VQMMC (2.7V),
which some EEs claim is a little too close to the minimum for
comfort.
This is done in two steps. At first we try to find a VQMMC within
a 0.3V tolerance of VMMC and if this is not supported by the
supplying regulator we try to find a suitable voltage within the
whole 2.7V-3.6V area of the spec.
* The two step approach is currently necessary, as the used
regulator_set_voltage_triplet(min, target, max) uses a simple
implementation that just tries two basic steps:
regulator_set_voltage(target, max);
regulator_set_voltage(min, target);
So with only one step with 2.7-3.6V borders, if a suitable voltage
is a bit below VMMC, we would directly get the lowest 2.7V
which some boards (like Rockchips) don't like at all.
* When setting the signal voltage to 1.8V or 1.2V we aim for that
specific voltage instead of picking the lowest one in the range.
* We very purposely don't print errors in mmc_regulator_set_vqmmc().
There are cases where the MMC core will try several different
voltages and we don't want to pollute the logs.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
We will shortly need the calculation of an ocr-bit to the actual
voltage in a second place too, so move it from mmc_regulator_set_ocr
to a common function mmc_ocrbitnum_to_vdd to make that possible.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
MMC_CLKGATE was once invented to save power by gating the bus clock at
request inactivity. At that time it served its purpose. The modern way to
deal with power saving for these scenarios, is by using runtime PM.
Nowadays, several host drivers have deployed runtime PM, but for those
that haven't and which still cares power saving at request inactivity,
it's certainly time to deploy runtime PM as it has been around for several
years now.
To simplify code to mmc core and thus decrease maintenance efforts, this
patch removes all code related to MMC_CLKGATE.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Some sdio wifi chips will not work properly if we try to start new
sdio-rw requests while the device is signalling that it is busy.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
As mmc_claim_host() invokes pm_runtime_get_sync() for the mmc host device,
it's important that the host is kept claimed for *all* accesses to it via
the host_ops callbacks.
In some code paths for SDIO, particularly related to the PM support,
mmc_power_off|up() is invoked without keeping the host claimed. Let's fix
these.
Moreover, mmc_start|stop_host() also invokes mmc_power_off|up() without
claiming the host, let's fix these as well.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
When get a CRC error, start the mmc_retune, it will issue CMD19/CMD21
to do tune, assume there were 10 clock phase need to try, phase 0 to
phase 6 is ok, phase 7 to phase 9 is NG, we try it from 0 to 9, so
the last CMD19/CMD21 will get CRC error, host->need_retune was set and
cause mmc_retune was called, then dead loop of mmc_retune
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Fixes: bd11e8bd03 ("mmc: core: Flag re-tuning is needed on CRC errors")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The following panic is captured in ker3.14, but the issue still exists
in latest kernel.
---------------------------------------------------------------------
[ 20.738217] c0 3136 (Compiler) Unable to handle kernel NULL pointer dereference
at virtual address 00000578
......
[ 20.738499] c0 3136 (Compiler) PC is at _raw_spin_lock_irqsave+0x24/0x60
[ 20.738527] c0 3136 (Compiler) LR is at _raw_spin_lock_irqsave+0x20/0x60
[ 20.740134] c0 3136 (Compiler) Call trace:
[ 20.740165] c0 3136 (Compiler) [<ffffffc0008ee900>] _raw_spin_lock_irqsave+0x24/0x60
[ 20.740200] c0 3136 (Compiler) [<ffffffc0000dd024>] __wake_up+0x1c/0x54
[ 20.740230] c0 3136 (Compiler) [<ffffffc000639414>] mmc_wait_data_done+0x28/0x34
[ 20.740262] c0 3136 (Compiler) [<ffffffc0006391a0>] mmc_request_done+0xa4/0x220
[ 20.740314] c0 3136 (Compiler) [<ffffffc000656894>] sdhci_tasklet_finish+0xac/0x264
[ 20.740352] c0 3136 (Compiler) [<ffffffc0000a2b58>] tasklet_action+0xa0/0x158
[ 20.740382] c0 3136 (Compiler) [<ffffffc0000a2078>] __do_softirq+0x10c/0x2e4
[ 20.740411] c0 3136 (Compiler) [<ffffffc0000a24bc>] irq_exit+0x8c/0xc0
[ 20.740439] c0 3136 (Compiler) [<ffffffc00008489c>] handle_IRQ+0x48/0xac
[ 20.740469] c0 3136 (Compiler) [<ffffffc000081428>] gic_handle_irq+0x38/0x7c
----------------------------------------------------------------------
Because in SMP, "mrq" has race condition between below two paths:
path1: CPU0: <tasklet context>
static void mmc_wait_data_done(struct mmc_request *mrq)
{
mrq->host->context_info.is_done_rcv = true;
//
// If CPU0 has just finished "is_done_rcv = true" in path1, and at
// this moment, IRQ or ICache line missing happens in CPU0.
// What happens in CPU1 (path2)?
//
// If the mmcqd thread in CPU1(path2) hasn't entered to sleep mode:
// path2 would have chance to break from wait_event_interruptible
// in mmc_wait_for_data_req_done and continue to run for next
// mmc_request (mmc_blk_rw_rq_prep).
//
// Within mmc_blk_rq_prep, mrq is cleared to 0.
// If below line still gets host from "mrq" as the result of
// compiler, the panic happens as we traced.
wake_up_interruptible(&mrq->host->context_info.wait);
}
path2: CPU1: <The mmcqd thread runs mmc_queue_thread>
static int mmc_wait_for_data_req_done(...
{
...
while (1) {
wait_event_interruptible(context_info->wait,
(context_info->is_done_rcv ||
context_info->is_new_req));
static void mmc_blk_rw_rq_prep(...
{
...
memset(brq, 0, sizeof(struct mmc_blk_request));
This issue happens very coincidentally; however adding mdelay(1) in
mmc_wait_data_done as below could duplicate it easily.
static void mmc_wait_data_done(struct mmc_request *mrq)
{
mrq->host->context_info.is_done_rcv = true;
+ mdelay(1);
wake_up_interruptible(&mrq->host->context_info.wait);
}
At runtime, IRQ or ICache line missing may just happen at the same place
of the mdelay(1).
This patch gets the mmc_context_info at the beginning of function, it can
avoid this race condition.
Signed-off-by: Jialing Fu <jlfu@marvell.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Fixes: 2220eedfd7 ("mmc: fix async request mechanism ....")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
For some mass production of kingston eMMCs which adopt Phison's
firmware will meet an unrecoverable data conrruption occasionally
if performing trim due to a firmware bug confirmed by vendor. We
found it on Intel-C3230RK platform. So we add fixup of broken trim
for it.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
When requesting a trim for several bytes, everything up to the next
erase-group is erased. This causes data corruption.
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
In the (not so unlikely) case that the mmc controller timeout budget is
enough for exactly one erase-group, the simplification of allowing one
sector has an enormous performance penalty. We optimize this special case
by introducing a flag that prohibits erase-group boundary crossing, so
that we can allow trimming more than one sector at a time.
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Make a new function out of common code used for drive
strength selection.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
IO state variable drv_type could be set during card
initialization. Consequently, it must be reset to the
default value when setting the initial state.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Since the regulator used for the SDMMC IO voltage is not expected to
draw a lot of current, most systems will probably use an inexpensive
LDO for it. LDO regulators apparently have the feature that they
don't actively drive the voltage down--they wait for other components
in the system to drag the voltage down. Thus they will transition
faster under heavy loads and slower under light loads.
During an SDMMC voltage change from 3.3V to 1.8V, we are almost
certainly under a light load. To be specific:
* The regulator is hooked through pulls to CMD0-3 and DAT. Probably
the CMD pulls are something like 47K and the DAT is something like
10K.
* The card is supposed to be driving DAT0-3 low during voltage change
which will draw _some_ current, but not a lot.
* The regulator is also provided to the SDMMC host controller, but the
SDMMC host controller is in open drain mode during the voltage
change and so shouldn't be drawing much current.
In order to keep the SDMMC host working properly (or for noise
reasons), there might also be a capacitor attached to the SDMMC IO
regulator. This also will have the effect of slowing down transitions
of the regulator, especially under light loads.
From experimental evidence, we've seen the voltage change fail if the
card doesn't detect that the voltage fell to less than about 2.3V when
we turn on the clock. On one device (that admittedly had a 47K CMD
pullup instead of a 10K CMD pullup) we saw that the voltage was just
about 2.3V after 5ms and thus the voltage change would sometimes fail.
Doubling the delay gave margin and made the voltage change work 100%
of the time, despite the slightly weaker CMD pull.
At the moment submitting this as an RFC patch since my problem _could_
be fixed by increasing the pull strength (or using a smaller
capacitor). However being a little bit more lenient to strange
hardware could also be a good thing.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Russell King
Wolfram Sang
Jaehoon Chung
Ulf Hansson
Carlo Caione
ludovic.desroches@atmel.com
Douglas Anderson
Heiko Stuebner
Hans de Goede
Chaotian Jing
Jialing Fu
Shawn Lin
Robin van der Gracht
David Jander
Adrian Hunter