Update documentation for sdio_claim_irq to downgrade the wording
about doing recursive claims in an IRQ handler from 'must not' to
'should not'. This clarifies that recursive claims are supported,
but not the recommended (best) practice
Signed-off-by: Joel Cunningham <joel.cunningham@garmin.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Currently the host can be claimed by a task. Change this so that the host
can be claimed by a context that may or may not be a task. This provides
for the host to be claimed by a block driver queue to support blk-mq, while
maintaining compatibility with the existing use of mmc_claim_host().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ,
the SDIO IRQs are processed from a dedicated kernel thread. For these
cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new
SDIO IRQ.
Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be
invoked to temporary disable the IRQs, before the kernel thread is woken up
to process it. When processing of the IRQs are completed, they are
re-enabled by the kernel thread, again via invoking the host's
->enable_sdio_irq().
The observation from this, is that the execution path is being unnecessary
complex, as the host driver already knows that it needs to temporary
disable the IRQs before signaling a new one. Moreover, replacing the kernel
thread with a work/workqueue would not only greatly simplify the code, but
also make it more robust.
To address the above problems, let's continue to build upon the support for
MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be
processed without using the clumsy kernel thread and without the ping-pong
calls of the host's ->enable_sdio_irq() callback for each processed IRQ.
Therefore, let's add new API sdio_signal_irq(), which enables hosts to
signal/process SDIO IRQs by using a work/workqueue, rather than using the
kernel thread.
Add also a new host callback ->ack_sdio_irq(), which the work invokes when
the SDIO IRQs have been processed. This informs the host about when it
shall re-enable the SDIO IRQs. Potentially, we could re-use the existing
->enable_sdio_irq() callback instead of adding a new one, however it has
turned out that it's more convenient for hosts to get this information via
a separate callback.
Hosts that wants to use this new method to signal/process SDIO IRQs, must
enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq()
callback.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
In cases when MMC_CAP2_SDIO_IRQ_NOTHREAD is set, there is a minor window
for when the mmc host could call sdio_run_irqs(), while in fact an SDIO
func driver could have decided to released the SDIO IRQ via a call to
sdio_release_irq(). In this scenario, processing of the SDIO IRQs are done
even if there is none IRQ claimed, which is not what we want.
To prevent this from happen, close the window by validating that at least
one SDIO IRQs is claimed, before deciding to process them.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.
Create empty placeholder header that maps to <linux/types.h>.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A significant amount of functions and other definitions are available
through the public mmc card.h header file. Let's slim down this public mmc
interface, as to prevent users from abusing it, by moving some of the
functions/definitions to private mmc header files.
This change concentrates on moving the functions into private mmc headers,
following changes may continue with additional clean-ups.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
A significant amount of functions are available through the public mmc
core.h header file. Let's slim down this public mmc interface, as to
prevent users from abusing it, by moving some of the functions to private
mmc header files.
This change concentrates on moving the functions into private mmc headers,
following changes may continue with additional clean-ups, as an example
some functions can be turned into static.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
BUG_ONs doesn't help anything except for stop the system from
running. If it occurs, it implies we should deploy proper error
handling for that. So this patch is gonna discard these meaningless
BUG_ONs and deploy error handling if needed.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
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>
Use the much more common pr_warn instead of pr_warning.
Other miscellanea:
o Coalesce formats
o Realign arguments
o Remove extra spaces when coalescing formats
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
781e989cf5 ("mmc: sdhci: convert to new SDIO IRQ handling") and
bf3b5ec66b ("mmc: sdio_irq: rework sdio irq handling") disabled
the use of our own custom threaded IRQ handler, but left in an
unconditional wake_up_process() on that handler at resume-time.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=80151
In addition, the check for MMC_CAP_SDIO_IRQ capability is added
before enable sdio IRQ.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <chris@printf.net>
Signed-off-by: Fu Zhonghui <zhonghui.fu@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Rather than the SDIO support spawning it's own thread for handling card
interrupts, use the generic IRQ infrastructure for this, triggering it
from the host interface's interrupt handling directly.
This avoids a race between the parent thread waiting to receive an
interrupt response from the card, and the slow startup from the sdio
irq thread, which can occur as a result of high system load (eg, while
udev is running.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Markus Pargmann <mpa@pengutronix.de>
Tested-by: Stephen Warren <swarren@nvidia.com>
[Ulf Hansson] Resolved conflict
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Polling SDIO_CCCR_INTx could create a fake interrupt with Marvell
SD8797 card. Add a quirk to handle this case. The fixup here is
to issue a dummy CMD52 read to function 0 register 0xff, and this
dummy read must be right after SDIO_CCCR_INTx is read.
Patch has been verified on a dw_mmc controller (Samsung Chromebook)
with MMC_CAP_SDIO_IRQ disabled.
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
Commit 06e8935feb ("optimized SDIO IRQ handling for single irq")
introduced some spurious calls to SDIO function interrupt handlers,
such as when the SDIO IRQ thread is started, or the safety check
performed upon a system resume. Let's add a flag to perform the
optimization only when a real interrupt is signaled by the host
driver and we know there is no point confirming it.
Reported-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Ensure clocks are always enabled before any interaction with the
host controller driver. This makes sure that there is no race
between host execution and the core layer turning off clocks
in different context with clock gating framework.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
These two basic defines were everywhere, simply because module.h
was also everywhere. But we are cleaning up the latter. So make
the exporters actually call out their need for the include.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
All the files using printk function for displaying kernel messages
in the mmc driver have been replaced with corresponding macro.
Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
If there is only 1 function interrupt registered it is possible to
improve performance by directly calling the irq handler and avoiding
the overhead of reading the CCCR registers.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Make sure we can be woken from the forced sleep that is done on errors.
Removing a card often results in -ENOMEDIUM or -EILSEQ so we previously
locked up the removal process for a second.
We could completely exit on -ENOMEDIUM, but it might be a transient
glitch so treat it like any other error.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Currently we print a message about some bad states wrt function IRQ
handlers but return 0 from process_sdio_pending_irqs() nevertheless.
This can lead to an infinite loop as nothing might have cleared the
condition for the pending card interrupt from the host controller by
the time host->ops->enable_sdio_irq(host, 1) is called.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
If func is actually null we won't get much from sdio_func_id(func).
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The interrupt polling frequency is a compromise between power usage and
interrupt latency. Unfortunately, it affects throughput rather severely
for devices which require an interrupt for every chunk of data.
By making the polling frequency adaptive, we get better throughput with
those devices without sacficing too much power. Polling will quickly
increase when there is an actual interrupt, and slowly fall back to the
idle frequency when the interrupts stop coming.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Replace all cases of BUG_ON with WARN_ON where there is a chance
(with varying degrees of slim) that the kernel can continue without
incidence.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
