The IRQ handler, mmci_irq(), loops until all status bits have been cleared.
However, the status bit signaling busy in variant->busy_detect_flag, may be
set even if busy detection isn't monitored for the current request.
This may be the case for the CMD11 when switching the I/O voltage, which
leads to that mmci_irq() busy loops in IRQ context. Fix this problem, by
clearing the status bit for busy, before continuing to validate the
condition for the loop. This is safe, because the busy status detection has
already been taken care of by mmci_cmd_irq().
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Let's cleanup the mmci_cmd_irq() a bit, to make the busy detect code more
clear.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch allows to get datactrl configuration specific
at variant. This introduce more flexibility on datactlr
value.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
As mmci_variant_init() is a local function to mmci.c, let's convert it into
static.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
It's good practice to share functions via header files, rather than from
the c-files. Therefore, let's move sdmmc_variant_init() to mmci.h.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Ludovic Barre <ludovic.barre@st.com>
Tested-by: Ludovic Barre <ludovic.barre@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
It seems a bit silly to have a header file to share only the
qcom_variant_init() function. So, let's just drop it and move the
declaration of the function into the common mmci.h instead.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Having mmci_dmae_start() to invoke the shared function, dml_start_xfer(),
explicitly for the qcom variant isn't very nice. Let's clean up this code
by moving the qcom specific parts into the qcom ->dma_start() callback and
then drop dml_start_xfer() altogether.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
The current approach with sending a CMD12 (STOP_TRANSMISSION) to complete a
data transfer request, either because of using the open-ended transmission
type or because of receiving an error during a pre-defined data transfer,
isn't sufficient for the STM32 sdmmc variant. More precisely, this variant
needs to clear the DPSM ("Data Path State Machine") by sending a CMD12, for
all failing ADTC commands.
Support this, by adding a struct mmc_command inside the struct mmci_host
and initialize it to a CMD12 during ->probe(). Let's also add checks for
the new conditions, to enable mmci_data_irq() and mmci_cmd_irq() to
postpone the calls to mmci_request_end(), but instead send the CMD12.
Cc: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Barre <ludovic.barre@st.com>
The argument "override_active_level" made it possible to
enforce a specific polarity on the write-protect
GPIO line. All callers in the kernel pass "false" to this
call after I have converted all drivers to use GPIO machine
descriptors, so remove the argument and clean out this.
This kind of polarity inversion should be handled by the
GPIO descriptor inside the GPIO library if needed.
This rids us of one instance of the kludgy calls into
the gpiod_get_raw_value() API.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
On cmd12 (STOP_TRANSMISSION), STM32 sdmmc variant needs to set
cmdstop bit in command register. The CPSM ("Command Path State Machine")
treats the command as a Stop Transmission command and signals
abort to the DPSM ("Data Path State Machine").
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Refer to "4.15 set block count command" of sd specification:
Host needs to issue CMD12 if any error is detected in
the CMD18 and CMD25 operations.
In sbc case, the data->stop is fill by framework.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds a stm32 sdmmc variant, rev 1.1.
Introduces a new Manufacturer id "0x53, ascii 'S' to define
new stm32 sdmmc family with clean range of amba
revision/configurations bits (corresponding to sdmmc_ver
register with major/minor fields).
Add 2 variants properties:
-dma_lli, to enable link list support.
-stm32_idmabsize_mask, defines the range of SDMMC_IDMABSIZER register
which specify the number bytes per buffer.
DT properties for sdmmc:
-Indicate signal directions (only one property
for d0dir, d123dir, cmd_dir)
-Select command and data phase relation.
-Select "clock in" from an external driver.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The STM32 sdmmc variant has a different clock divider.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds a optional reset management.
STM32 sdmmc variant needs to reset hardware block
during the power cycle procedure (for re-initialization).
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds a boolean property to not read datacnt register.
Needed to support the STM32 sdmmc variant. MMCIDATACNT
register should be read only after the data transfer is completed.
When reading after an error event the read data count value may be
different from the real number of data bytes transferred.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds a boolean property to allow to write datactrl
before to send command, whatever the command type (read or write).
Needed to support the STM32 sdmmc variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch allows to define specific pio mask for variants.
Needed to support the STM32 sdmmc variant which has some bits
with different meaning (bits: 21,20,13,12,9)
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds datactrl variant property to define
dpsm enable bit. Needed to support the STM32 variant
(STM32 has no dpsm enable bit).
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds command variant properties to define
cpsm enable bit and responses.
Needed to support the STM32 variant (shift of cpsm bit,
specific definition of commands response).
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
All variants don't pretend to have a startbiterr.
-While data error check, if status register return an error
(like MCI_DATACRCFAIL) we must avoid to check MCI_STARTBITERR
(if not desired).
-expand start_err to MCI_IRQENABLE to avoid to set this bit by default.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch allows to define a datactrl block size
by variant, requested by STM32 sdmmc variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds set_clkreg and set_pwrreg callbacks
at mmci_host_ops to allow to call specific variant.
extends visibility of mmci_write_clk/pwrreg functions
to be used into specific file variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds validate_data callback at mmci_host_ops
to check specific constraints of variant.
Move mmci_validate_data function to regroup mmci_host_ops interfaces.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds dma_error callback at mmci_host_ops
to allow to call specific variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds dma_finalize callback at mmci_host_ops
to allow to call specific variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds dma_start callback to mmci_host_ops.
Create a generic mmci_dma_start function which regroup
common action between variant.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds prepare/unprepare callbacks to mmci_host_ops.
Like this mmci_pre/post_request can be generic, mmci_prepare_data
and mmci_unprepare_data provide common next_cookie management.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch merges the prepare data functions.
This allows to define a single access to prepare data service.
This prepares integration for mmci host ops.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
-Introduces dma_priv pointer to define specific
needs for each dma engine. This patch is needed to prepare
sdmmc variant with internal dma which not use dmaengine API.
-Moves next cookie to mmci host structure to share same cookie
management between all variants.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch creates a common mmci_dma_setup/release which calls
dma_setup/release callbacks of mmci_host_ops and manages
common features like use_dma... If there is a fallbacks to
pio mode, dma functions must check use_dma.
error management:
-mmci_dmae_setup fail if Tx and Rx dma channels are not defined
-qcom_dma_setup fail if one of both dma channels is not defined,
Qcom has no specific resource to release, just mmci dmae resource.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch internalizes the dma_inprogress into mmci dma interfaces.
This allows to simplify and prepare the next dma callbacks
for mmci host ops. dma_inprogress is called in mmci_dma_data_error
and mmci_dma_finalize.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch internalizes the management of dma map/unmap into
mmci dma interfaces. This allows to simplify and prepare the next dma
callbacks for mmci host ops.
mmci_dma_unmap was called in mmci_data_irq & mmci_cmd_irq functions
and can be integrated in mmci_dma_data_error.
Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
All the machines using the MMCI are passing GPIOs for the
card detect and write protect using the device tree or
descriptor table (one single case, Integrator/AP IM-PD1).
Drop support for passing global GPIO numbers through
platform data, noone is using it.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
As a first step to improve the variant specific code for mmci, add a
->dma_setup() callback to the struct mmci_host_ops.
To show its use, let's deploy the callback for the qcom dml, which involves
also to the assign the mmci_host_ops pointer from the variant ->init()
callback.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
To be able to better support different mmci variants, we need to be able to
use variant specific callbacks, rather than continue to sprinkle the code
with additional variant data. To move in this direction, let's add an
optional ->init() callback to the variant data struct, which variants shall
use to assign the mmci_host_ops pointer.
Using an ->init() callback enables us to partition the code between
different files. To allow separate mmci variant files to implement the
variant specifics, let's also move the definition of the struct
variant_data to the common mmci header file.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
On !RT interrupt runs with interrupts disabled. On RT it's in a
thread, so no need to disable interrupts at all.
Remove the local_irq_save() invocation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Fixes: f9bb304ce8 ("mmc: mmci: Add support for setting pad type via pinctrl")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
STM32F4 and STM32F7 MCUs has a SDIO controller that looks like
an ARM PL810.
This patch adds the STM32 variant so that mmci driver supports it.
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If variant hasn't the control bit to switch pads in opendrain mode,
we can achieve the same result by asking to the pinmux driver to
configure pins for us.
This patch make the mmci driver able to do this whenever needed.
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch prepares for supporting STM32 variant which doesn't
have opendrain bit in MMCIPOWER register.
ST others variant (u300, nomadik and ux500) uses MCI_OD bit whereas
others variants uses MCI_ROD bit.
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch prepares for supporting the STM32 variant that
has no such bit in the status register.
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Two mask registers are used in order to select which events have to
actually generate an interrupt on each IRQ line.
It seems that in the single-IRQ case it's assumed that the IRQs lines
are simply OR-ed, while the two mask registers are still present. The
driver still programs the two mask registers separately.
However the STM32 variant has only one IRQ, and also has only one mask
register.
This patch prepares for STM32 variant support by making the driver using
only one mask register.
This patch also optimize the MMCIMASK1 mask usage by caching it into
host->mask1_reg which avoid to read it into mmci_irq().
Tested only on STM32 variant. RFT for variants other than STM32
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.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>
amba_id are not supposed to change at runtime. All functions
working with const amba_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
commit 64b12a68a9
"mmc: core: fix prepared requests while doing bkops"
is fixing a bug in the wrong way. A bug in the MMCI
device driver is fixed by amending the MMC core.
Thinking about it: what the pre- and post-callbacks
are doing is to essentially map and unmap SG lists
for DMA transfers. Why would we not be able to do that
just because a BKOPS command is sent inbetween?
Having to unprepare/prepare the next asynchronous
request for DMA seems wrong.
Looking the backtrace in that commit we can see what
the real problem actually is:
mmci_data_irq() is calling mmci_dma_unmap() twice
which is goung to call arm_dma_unmap_sg() twice
and v7_dma_inv_range() twice for the same sglist
and that will crash.
This happens because a request is prepared, then
a BKOPS is sent. The IRQ completing the BKOPS command
goes through mmci_data_irq() and thinks that a DMA
operation has just been completed because
dma_inprogress() reports true. It then proceeds to
unmap the sglist.
But that was wrong! dma_inprogress() should NOT be
true because no DMA was actually in progress! We had
just prepared the sglist, and the DMA channel
dma_current has been configured, but NOT started!
Because of this, the sglist is already unmapped when
we get our actual data completion IRQ, and we are
unmapping the sglist once more, and we get this crash.
Therefore, we need to revert this solution pushing
the problem to the core and causing problems, and
instead augment the implementation such that
dma_inprogress() only reports true if some DMA has
actually been started.
After this we can keep the request prepared during the
BKOPS and we need not unprepare/reprepare it.
Fixes: 64b12a68a9 ("mmc: core: fix prepared requests while doing bkops")
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This fixes a race condition that may occur whenever ST micro busy end
interrupt is raised just after being unmasked but before leaving mmci
interrupt context.
A dead-lock has been found if connecting mmci ST Micro variant whose amba
id is 0x10480180 to some new eMMC that supports internal caches. Whenever
mmci driver enables cache control by programming eMMC's EXT_CSD register,
block driver may request to flush the eMMC internal caches causing mmci
driver to send a MMC_SWITCH command to the card with FLUSH_CACHE operation.
And because busy end interrupt may be mistakenly cleared while not yet
processed, this mmc request may never complete. As a result, mmcqd task
may be stuck forever.
Here is an instance caught by lockup detector which shows that mmcqd task
was hung while waiting for mmc_flush_cache command to complete:
..
[ 240.251595] INFO: task mmcqd/1:52 blocked for more than 120 seconds.
[ 240.257973] Not tainted 4.1.13-00510-g9d91424 #2
[ 240.263109] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 240.270955] mmcqd/1 D c047504c 0 52 2 0x00000000
[ 240.277359] [<c047504c>] (__schedule) from [<c04754a0>] (schedule+0x40/0x98)
[ 240.284418] [<c04754a0>] (schedule) from [<c0477d40>] (schedule_timeout+0x148/0x188)
[ 240.292191] [<c0477d40>] (schedule_timeout) from [<c0476040>] (wait_for_common+0xa4/0x170)
[ 240.300491] [<c0476040>] (wait_for_common) from [<c02efc1c>] (mmc_wait_for_req_done+0x4c/0x13c)
[ 240.309224] [<c02efc1c>] (mmc_wait_for_req_done) from [<c02efd90>] (mmc_wait_for_cmd+0x64/0x84)
[ 240.317953] [<c02efd90>] (mmc_wait_for_cmd) from [<c02f5b14>] (__mmc_switch+0xa4/0x2a8)
[ 240.325964] [<c02f5b14>] (__mmc_switch) from [<c02f5d40>] (mmc_switch+0x28/0x30)
[ 240.333389] [<c02f5d40>] (mmc_switch) from [<c02f0984>] (mmc_flush_cache+0x54/0x80)
[ 240.341073] [<c02f0984>] (mmc_flush_cache) from [<c02ff0c4>] (mmc_blk_issue_rq+0x114/0x4e8)
[ 240.349459] [<c02ff0c4>] (mmc_blk_issue_rq) from [<c03008d4>] (mmc_queue_thread+0xc0/0x180)
[ 240.357844] [<c03008d4>] (mmc_queue_thread) from [<c003cf90>] (kthread+0xdc/0xf4)
[ 240.365339] [<c003cf90>] (kthread) from [<c0010068>] (ret_from_fork+0x14/0x2c)
..
..
[ 240.664311] INFO: task partprobe:564 blocked for more than 120 seconds.
[ 240.670943] Not tainted 4.1.13-00510-g9d91424 #2
[ 240.676078] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 240.683922] partprobe D c047504c 0 564 486 0x00000000
[ 240.690318] [<c047504c>] (__schedule) from [<c04754a0>] (schedule+0x40/0x98)
[ 240.697396] [<c04754a0>] (schedule) from [<c0477d40>] (schedule_timeout+0x148/0x188)
[ 240.705149] [<c0477d40>] (schedule_timeout) from [<c0476040>] (wait_for_common+0xa4/0x170)
[ 240.713446] [<c0476040>] (wait_for_common) from [<c01f3300>] (submit_bio_wait+0x58/0x64)
[ 240.721571] [<c01f3300>] (submit_bio_wait) from [<c01fbbd8>] (blkdev_issue_flush+0x60/0x88)
[ 240.729957] [<c01fbbd8>] (blkdev_issue_flush) from [<c010ff84>] (blkdev_fsync+0x34/0x44)
[ 240.738083] [<c010ff84>] (blkdev_fsync) from [<c0109594>] (do_fsync+0x3c/0x64)
[ 240.745319] [<c0109594>] (do_fsync) from [<c000ffc0>] (ret_fast_syscall+0x0/0x3c)
..
Here is the detailed sequence showing when this issue may happen:
1) At probe time, mmci device is initialized and card busy detection based
on DAT[0] monitoring is enabled.
2) Later during run time, since card reported to support internal caches, a
MMCI_SWITCH command is sent to eMMC device with FLUSH_CACHE operation. On
receiving this command, eMMC may enter busy state (for a relatively short
time in the case of the dead-lock).
3) Then mmci interrupt is raised and mmci_irq() is called:
MMCISTATUS register is read and is equal to 0x01000440. So the following
status bits are set:
- MCI_CMDRESPEND (= 6)
- MCI_DATABLOCKEND (= 10)
- MCI_ST_CARDBUSY (= 24)
Since MMCIMASK0 register is 0x3FF, status variable is set to 0x00000040 and
BIT MCI_CMDRESPEND is cleared by writing MMCICLEAR register.
Then mmci_cmd_irq() is called. Considering the following conditions:
- host->busy_status is 0,
- this is a "busy response",
- reading again MMCISTATUS register gives 0x1000400,
MMCIMASK0 is updated to unmask MCI_ST_BUSYEND bit.
Thus, MMCIMASK0 is set to 0x010003FF and host->busy_status is set to wait
for busy end completion.
Back again in status loop of mmci_irq(), we quickly go through
mmci_data_irq() as there are no data in that case. And we finally go
through following test at the end of while(status) loop:
/*
* Don't poll for busy completion in irq context.
*/
if (host->variant->busy_detect && host->busy_status)
status &= ~host->variant->busy_detect_flag;
Because status variable is not yet null (is equal to 0x40), we do not leave
interrupt context yet but we loop again into while(status) loop. So we run
across following steps:
a) MMCISTATUS register is read again and this time is equal to 0x01000400.
So that following bits are set:
- MCI_DATABLOCKEND (= 10)
- MCI_ST_CARDBUSY (= 24)
Since MMCIMASK0 register is equal to 0x010003FF:
b) status variable is set to 0x01000000.
c) MCI_ST_CARDBUSY bit is cleared by writing MMCICLEAR register.
Then, mmci_cmd_irq() is called one more time. Since host->busy_status is
set and that MCI_ST_CARDBUSY is set in status variable, we just return from
this function.
Back again in mmci_irq(), status variable is set to 0 and we finally leave
the while(status) loop. As a result we leave interrupt context, waiting for
busy end interrupt event.
Now, consider that busy end completion is raised IN BETWEEN steps 3.a) and
3.c). In such a case, we may mistakenly clear busy end interrupt at step
3.c) while it has not yet been processed. This will result in mmc command
to wait forever for a busy end completion that will never happen.
To fix the problem, this patch implements the following changes:
Considering that the mmci seems to be triggering the IRQ on both edges
while monitoring DAT0 for busy completion and that same status bit is used
to monitor start and end of busy detection, special care must be taken to
make sure that both start and end interrupts are always cleared one after
the other.
1) Clearing of card busy bit is moved in mmc_cmd_irq() function where
unmasking of busy end bit is effectively handled.
2) Just before unmasking busy end event, busy start event is cleared by
writing card busy bit in MMCICLEAR register.
3) Finally, once we are no more busy with a command, busy end event is
cleared writing again card busy bit in MMCICLEAR register.
This patch has been tested with the ST Accordo5 machine, not yet supported
upstream but relies on the mmci driver.
Signed-off-by: Sarang Mairal <sarang.mairal@garmin.com>
Signed-off-by: Jean-Nicolas Graux <jean-nicolas.graux@st.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The void (*pre_req) callback in the struct mmc_host_ops vtable
is passing an argument "is_first_req" indicating whether this is
the first request or not.
None of the in-kernel users use this parameter: instead, since
they all just do variants of dma_map* they use the DMA cookie
to indicate whether a pre* callback has already been done for
a request when they decide how to handle it.
Delete the parameter from the callback and all users, as it is
just pointless cruft.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
