There are a few places with the same functionality. This patch creates
two functions omap_hsmmc_set_bus_width() and omap_hsmmc_set_bus_mode()
to do the job.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
There are two pieces of code which are similar, but not the same.
Each of them contains a bug.
The SYSCTL register should be read before writing to it in
omap_hsmmc_context_restore() to retain the state of the reserved bits.
Before setting the clock divisor and DTO bits the value from the SYSCTL
register should be masked properly. We were lucky to have no problems
with DTO bits. So, make sure we have clear DTO bits properly in
omap_hsmmc_set_ios().
Additionally get rid of msleep(1). The actual time is rarely higher
than 30us on OMAP 3630.
The resulting pieces of code are refactored into the
omap_hsmmc_set_clock() function.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
There is similar code in two functions which enable the clock. Refactor
this code to omap_hsmmc_start_clock(). Re-use omap_hsmmc_stop_clock() in
omap_hsmmc_context_restore() as well.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
There are two places where the same calculations are done.
Let's split them into a separate function.
In addition, simplify by using the DIV_ROUND_UP kernel macro.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Move the min and max frequency constants to the definition block in
the source file.
Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
CERR and BADA were in the wrong place and there are only
32 not 35.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
We already check for ongoing async transfers when handling discard
requests, but not in mmc_blk_issue_flush(). This patch fixes that
omission.
Tested with an SDHCI controller and eMMC4.41.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Per Forlin <per.forlin@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
After runtime conversion to handle clk, iclk node is not used.
However fclk node is still used to get clock rate.
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
* Add runtime pm support to HSMMC host controller.
* Use runtime pm API to enable/disable HSMMC clock.
* Use runtime autosuspend APIs to enable auto suspend delay.
Based on OMAP HSMMC runtime implementation by Kevin Hilman and
Kishore Kadiyala.
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
lazy_disable framework in OMAP HSMMC manages multiple low power states and
card is powered off after inactivity time of 8 seconds. Based on previous
discussion on the list, card power (regulator) handling (when to power
OFF/ON) should ideally be handled by core layer. Remove usage of lazy
disable to allow core layer _only_ to handle card power. With the removal
of lazy disable framework, MMC regulators are left ON until MMC_POWER_OFF
via set_ios.
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Non default Drive Strength cannot be set automatically. It is a function
of the board design and only if there is a specific platform handler can
it be set. The platform handler needs to take into account the board
design. Pass to the platform code the necessary information.
For example: The card and host controller may indicate they support HIGH
and LOW drive strength. There is no way to know what should be chosen
without specific board knowledge. Setting HIGH may lead to reflections
and setting LOW may not suffice. There is no mechanism (like ethernet
duplex or speed pulses) to determine what should be done automatically.
If no platform handler is defined -- use the default value.
Signed-off-by: Philip Rakity <prakity@marvell.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Change mmc_blk_issue_rw_rq() to become asynchronous.
The execution flow looks like this:
* The mmc-queue calls issue_rw_rq(), which sends the request
to the host and returns back to the mmc-queue.
* The mmc-queue calls issue_rw_rq() again with a new request.
* This new request is prepared in issue_rw_rq(), then it waits for
the active request to complete before pushing it to the host.
* When the mmc-queue is empty it will call issue_rw_rq() with a NULL
req to finish off the active request without starting a new request.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add an additional mmc queue request instance to make way for two active
block requests. One request may be active while the other request is
being prepared.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Break out code without functional changes. This simplifies the code and
makes way for handling two parallel requests.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar<sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Break out code from mmc_blk_issue_rw_rq to create a block request prepare
function. This doesn't change any functionallity. This helps when handling
more than one active block request.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
The way the request data is organized in the mmc queue struct, it only
allows processing of one request at a time. This patch adds a new struct
to hold mmc queue request data such as sg list, request, blk request and
bounce buffers, and updates any functions depending on the mmc queue
struct. This prepares for using multiple active requests in one mmc queue.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add a test that measures how the mmc bandwidth depends on the numbers of
sg elements in the sg list. The transfer size if fixed and sg length goes
from a few up to 512. The purpose is to measure overhead caused by
multiple sg elements.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add four tests for read and write performance per
different transfer size, 4k to 4M.
* Read using blocking mmc request
* Read using non-blocking mmc request
* Write using blocking mmc request
* Write using non-blocking mmc request
The host driver must support pre_req() and post_req()
in order to run the non-blocking test cases.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar<sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add a debugfs file "testlist" to print all available tests.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar<sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
pre_req() runs dma_map_sg() and prepares the dma descriptor for the next
mmc data transfer. post_req() runs dma_unmap_sg. If not calling pre_req()
before mmci_request(), mmci_request() will prepare the cache and dma just
like it did it before. It is optional to use pre_req() and post_req()
for mmci.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
pre_req() runs dma_map_sg(), post_req() runs dma_unmap_sg. If not calling
pre_req() before omap_hsmmc_request(), dma_map_sg will be issued before
starting the transfer. It is optional to use pre_req(). If issuing
pre_req(), post_req() must be called as well.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Previously there has only been one function mmc_wait_for_req()
to start and wait for a request. This patch adds:
* mmc_start_req() - starts a request wihtout waiting
If there is on ongoing request wait for completion
of that request and start the new one and return.
Does not wait for the new command to complete.
This patch also adds new function members in struct mmc_host_ops
only called from core.c:
* pre_req - asks the host driver to prepare for the next job
* post_req - asks the host driver to clean up after a completed job
The intention is to use pre_req() and post_req() to do cache maintenance
while a request is active. pre_req() can be called while a request is
active to minimize latency to start next job. post_req() can be used after
the next job is started to clean up the request. This will minimize the
host driver request end latency. post_req() is typically used before
ending the block request and handing over the buffer to the block layer.
Add a host-private member in mmc_data to be used by pre_req to mark the
data. The host driver will then check this mark to see if the data is
prepared or not.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
This driver has been used for years with this option enabled.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Take care of slots while going to suspend state.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Unless MMC_CAP_8_BIT_DATA is set, the bus width defaults to 4.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
And hook platform_8bit_width to support 8-bit bus width.
Signed-off-by: Major Lee <major_lee@wistron.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
If an error occurs mid way through a transaction (such as a missing CRC
status response after the 2nd block written out of 3), then the FIFO may
still contain data which will interfere with the next transaction.
Therefore after an error has been detected, reset the fifo using the
CTRL register.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
When a data write isn't acknowledged by the card (so no CRC status token
is detected after the data), the error -EIO is returned instead of the
-ETIMEDOUT expected by mmc_test 15 - "Correct xfer_size at write (start
failure)" and 17 "Correct xfer_size at write (midway failure)". In PIO
mode the reported number of bytes transferred is also exaggerated since
the last block actually failed.
Handle the "Write no CRC" error specially, setting the error to
-ETIMEDOUT and setting the bytes_xferred to 0.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Remove error messages for timeout and CRC failure, since the error code
already indicates the problem.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
There are several situations when dw_mci_submit_data_dma() decides to
fall back to PIO mode instead of using DMA, due to a short (to avoid
overhead) or "complex" (e.g. with unaligned buffers) transaction, even
though host->use_dma is set. However dw_mci_stop_dma() decides whether
to stop DMA or set the EVENT_XFER_COMPLETE event based on host->use_dma.
When falling back to PIO mode this results in data timeout errors
getting missed and the driver locking up.
Therefore add host->using_dma to indicate whether the current
transaction is using dma or not, and adjust dw_mci_stop_dma() to use
that instead.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Wonil Choi <wonil22.choi@samsung.com>
Signed-off-by: Minho Ban <mhban@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
In general, SDHC hardware timeout cannot be avoided.
Accordingly, the maximum timeout is specified to limit
the maximum discard size.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some host controllers will not operate without a hardware
timeout that is limited in value. However large discards
require large timeouts, so there needs to be a way to
specify the maximum discard size.
A host controller driver may now specify the maximum discard
timeout possible so that max_discard_sectors can be calculated.
However, for eMMC when the High Capacity Erase Group Size
is not in use, the timeout calculation depends on clock
rate which may change. For that case Preferred Erase Size
is used instead.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
The use of flag ESDHC_FLAG_GPIO_FOR_CD_WP is all CD related. It does
not necessarily need to bother WP in the flag name.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
The function esdhc_readl_le intends to clear bit SDHCI_CARD_PRESENT,
when the card detect gpio tells there is no card. But it does not
clear the bit actually. The patch gives a fix on that.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
The issue was initially found by Eric Benard as below.
http://permalink.gmane.org/gmane.linux.ports.arm.kernel/108031
Not sure about other SDHCI based controller, but on Freescale eSDHC,
the SDHCI_INT_CARD_INSERT bits will be immediately set again when it
gets cleared, if a card is inserted. The driver need to mask the irq
to prevent interrupt storm which will freeze the system. And the
SDHCI_INT_CARD_REMOVE gets the same situation.
The patch fixes the problem based on the initial idea from
Eric Benard.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Eric Benard <eric@eukrea.com>
Tested-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
There is a race condition in the tmio_mmc_irq() interrupt handler,
caused by the presence of a while loop, which results in warnings of
spurious interrupts. This was found on an HP iPAQ hx4700 whose HTC
ASIC3 reportedly incorporates the Toshiba TC6380AF controller.
Towards the end of a multiple read (CMD18) operation the handler clears
the final RXRDY status bit in the first loop iteration, sees the DATAEND
status bit at the bottom of the loop, and so clears the DATAEND status
bit in the second loop iteration. However the DATAEND interrupt is still
queued in the system somewhere and can't be delivered until the handler
has returned. This second interrupt is then reported as spurious in the
next call to the handler. Likewise for single read (CMD17) operations.
And something similar occurs for multiple write (CMD25) and single write
(CMD24) operations, where CMDRESPEND and TXRQ status bits are cleared in
a single call.
In these cases the interrupt handler clears two separate interrupts when
it should only clear the one interrupt for which it was invoked. The fix
is to remove the while loop.
Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Only compile tmio_mmc_dma.o when CONFIG_MMC_SDHI is selected (as y or m).
Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Update functions for PIO pushing and pulling data to and from the FIFO
so that they can handle unaligned output buffers and unaligned buffer
lengths. This makes more of the tests in mmc_test pass.
Unaligned lengths in pulls are handled by reading the full FIFO item,
and storing the remaining bytes in a small internal buffer (part_buf).
The next data pull will copy data out of this buffer first before
accessing the FIFO again. Similarly, for pushes the final bytes that
don't fill a FIFO item are stored in the part_buf (or sent anyway if
it's the last transfer), and then the part_buf is included at the
beginning of the next buffer pushed.
Unaligned buffers in pulls are handled specially if the architecture
cannot do efficient unaligned accesses, by reading FIFO items into a
aligned local buffer, and memcpy'ing them into the output buffer, again
storing any remaining bytes in the internal buffer. Similarly for pushes
the buffer is memcpy'd into an aligned local buffer then written to the
FIFO.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
The FIFO_DEPTH hardware configuration parameter can be found from the
power-on value of RX_WMark in the FIFOTH register. This is used to
initialise the watermarks, but when calculating the number of free fifo
spaces a preprocessor definition is used which is hard coded to 32.
Fix reading the value out of FIFOTH (the default value in the RX_WMark
field is FIFO_DEPTH-1 not FIFO_DEPTH). Allow the fifo depth to be
overriden by platform data (since a bootloader may have changed FIFOTH
making auto-detection unreliable). Store the fifo_depth for later use.
Also fix the calculation to find the number of free bytes in the fifo to
include the fifo depth in the left shift by the data shift, since the
fifo depth is measured in fifo items not bytes.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Add brackets around use of the dev argument to the
mci_{read,write}{w,l,q}() macros, for extra safety.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Convert the card insert/remove tasklet to a workqueue, and call the
setpower platform specific callback without the spinlock held. This
means neither of the setpower or get_cd callbacks are called from atomic
context which allows them to sleep.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
When a request is made, the card presence is checked and the request is
queued. These two parts must be atomic with respect to card removal, or
a card removal could be handled in between, and the new request wouldn't
get cancelled until another card was inserted. Therefore move the
spinlock protection from dw_mci_queue_request() up into dw_mci_request()
to cover the presence check.
Note that the test_bit() used for the presence check isn't atomic
itself, so should have been protected by a spinlock anyway.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
DMA is only used for transactions exceeding a certain length, otherwise
PIO is used. The TXDR and RXDR interrupts are masked when in DMA mode
but still fire. When switching to PIO mode (e.g. to get SCR field when
an SD card is inserted) these interrupts are not cleared and so they
trigger the ISR as soon as they are unmasked. If the previous DMA did a
write, then the ISR will handle the TXDR interrupt even if the
transaction is a read, completing the transaction without modifying the
read buffer.
This is fixed primarily by clearing these two interrupts before
unmasking them when setting up PIO mode, and also by making the ISR more
robust by only handling TXDR/RXDR in the correct read/write direction.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Some controllers require waiting for the bus to become idle
before writing to some registers. I have implemented this
by adding a hook to sd_ctrl_write16() and implementing
a hook for SDHI which waits for the bus to become idle.
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
Move register access functions into a shared header.
Use sd_ctrl_write16 in tmio_mmc_dma.c:tmio_mmc_enable_dma().
Other than avoiding (trivial) open-coding, the motivation for
this is to allow platform-hooks in access functions to
be applied across all applicable accesses.
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
This reflects at least the current usage of this register
and I think it improves the readability of the code ever so slightly.
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
Check the status bits in the r/w command response for any errors.
If error bits are set, then we won't have seen any data transferred,
so it's pointless doing any further checking.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Command channel errors fall into four classes:
1. The command was issued with the card in the wrong state
2. The command failed to be received by the card correctly
3. The cards response failed to be received by the host (CRC error)
4. The card failed to respond to the card
For (1), in theory we should know that the card is in the correct state.
However, a failed stop command (or other failure) may result in the card
remaining in a data transfer state from the previous command. If we
detect this condition, we try to recover by sending a stop command.
For the initial commands (set block count and the read/write command)
no data will have been transferred. All that we need deal with is
retrying at this point. A failed stop command can be remedied as
above.
If we are unable to recover the card (eg, the card ignores our requests
for status, or we don't recognise the error code) then we immediately
fail the request.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
If the MMC_SEND_STATUS command is not successful, we should not return
a zero status word, but instead allow the caller to know positively
that an error occurred.
Convert the open-coded get_card_status() to use the helper function,
and provide definitions for the card state field.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
