144857ac52
commit ddca1092c4324c89cf692b5efe655aa251864b51 upstream.
The recent commit 0d84c3e6a5b2 ("mmc: core: Convert to
mmc_poll_for_busy() for erase/trim/discard") makes use of the
->card_busy() op for SD cards. This uncovered that the ->card_busy() op
in the Meson SDIO driver was never working right:
while polling the busy status with ->card_busy()
meson_mx_mmc_card_busy() reads only one of the two MESON_MX_SDIO_IRQC
register values 0x1f001f10 or 0x1f003f10. This translates to "three out
of four DAT lines are HIGH" and "all four DAT lines are HIGH", which
is interpreted as "the card is busy".
It turns out that no situation can be observed where all four DAT lines
are LOW, meaning the card is not busy anymore. Upon further research the
3.10 vendor driver for this controller does not implement the
->card_busy() op.
Remove the ->card_busy() op from the meson-mx-sdio driver since it is
not working. At the time of writing this patch it is not clear what's
needed to make the ->card_busy() implementation work with this specific
controller hardware. For all use-cases which have previously worked the
MMC_CAP_WAIT_WHILE_BUSY flag is now taking over, even if we don't have
a ->card_busy() op anymore.
Fixes: ed80a13bb4c4c9 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200416183513.993763-3-martin.blumenstingl@googlemail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.