Commit Graph

11 Commits

Author SHA1 Message Date
Stephen Warren d4d1144908 mmc: don't request CD IRQ until mmc_start_host()
As soon as the CD IRQ is requested, it can trigger, since it's an
externally controlled event. If it does, delayed_work host->detect will
be scheduled.

Many host controller probe()s are roughly structured as:

*_probe() {
    host = sdhci_pltfm_init();
    mmc_of_parse(host->mmc);
    rc = sdhci_add_host(host);
    if (rc) {
        sdhci_pltfm_free();
        return rc;
    }

In 3.17, CD IRQs can are enabled quite early via *_probe() ->
mmc_of_parse() -> mmc_gpio_request_cd() -> mmc_gpiod_request_cd_irq().

Note that in linux-next, mmc_of_parse() calls mmc_gpio*d*_request_cd()
rather than mmc_gpio_request_cd(), and mmc_gpio*d*_request_cd() doesn't
call mmc_gpiod_request_cd_irq(). However, this issue still exists if
mmc_gpio_request_cd() is called directly before mmc_start_host().

sdhci_add_host() may fail part way through (e.g. due to deferred
probe for a vmmc regulator), and sdhci_pltfm_free() does nothing to
unrequest the CD IRQ nor cancel the delayed_work. sdhci_pltfm_free() is
coded to assume that if sdhci_add_host() failed, then the delayed_work
cannot (or should not) have been triggered.

This can lead to the following with CONFIG_DEBUG_OBJECTS_* enabled, when
kfree(host) is eventually called inside sdhci_pltfm_free():

WARNING: CPU: 2 PID: 6 at lib/debugobjects.c:263 debug_print_object+0x8c/0xb4()
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x18

The object being complained about is host->detect.

There's no need to request the CD IRQ so early; mmc_start_host() already
requests it. For most SDHCI hosts at least, the typical call path that
does this is: *_probe() -> sdhci_add_host() -> mmc_add_host() ->
mmc_start_host(). Therefore, remove the call to mmc_gpiod_request_cd_irq()
from mmc_gpio_request_cd(). This also matches mmc_gpio*d*_request_cd(),
which already doesn't call mmc_gpiod_request_cd_irq().

However, some host controller drivers call mmc_gpio_request_cd() after
mmc_start_host() has already been called, and assume that this will also
call mmc_gpiod_request_cd_irq(). Update those drivers to explicitly call
mmc_gpiod_request_cd_irq() themselves. Ideally, these drivers should be
modified to move their call to mmc_gpio_request_cd() before their call
to mmc_add_host(). However that's too large a change for stable.

This solves the problem (eliminates the kernel error message above),
since it guarantees that the IRQ can't trigger before mmc_start_host()
is called.

The critical point here is that once sdhci_add_host() calls
mmc_add_host() -> mmc_start_host(), sdhci_add_host() is coded not to
fail. In other words, if there's a chance that mmc_start_host() may have
been called, and CD IRQs triggered, and the delayed_work scheduled,
sdhci_add_host() won't fail, and so cleanup is no longer via
sdhci_pltfm_free() (which doesn't free the IRQ or cancel the work queue)
but instead must be via sdhci_remove_host(), which calls mmc_remove_host()
-> mmc_stop_host(), which does free the IRQ and cancel the work queue.

CC: Russell King <linux@arm.linux.org.uk>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-23 09:01:36 +02:00
Minda Chen 1ba4c322ca mmc: sdhci-sirf: fix 8bit width enable by overwriting set_bus_width
the implementation of CSR SDHCI controller is a modified version of
the one described in the 1.0 specification, and not a normal 3.0
controller.
and 8bit-width enable bit of CSR MMC hosts is 3, while stardard hosts
use bit 5.
this patch fixes the functionality of 8bit transfer in mmc controllers
and improve performance for mmc0 a lot.

Signed-off-by: Minda Chen <Minda.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Reviewed-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-09 13:59:19 +02:00
Peter Griffin 2137f5d3b8 mmc: remove .owner field for drivers using module_platform_driver
This patch removes the superflous .owner field for drivers which
use the module_platform_driver API, as this is overriden in
platform_driver_register anyway.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2014-09-09 13:59:04 +02:00
Russell King 96d7b78cfc mmc: sdhci: convert sdhci_set_uhs_signaling() into a library function
Add sdhci_set_uhs_signaling() and always call the set_uhs_signaling
method.  This avoids quirks being added into sdhci_set_uhs_signaling().

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>
2014-05-22 08:33:11 -04:00
Russell King 1771059cf5 mmc: sdhci: convert sdhci_set_clock() into a library function
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>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-22 07:26:32 -04:00
Russell King 03231f9b78 mmc: sdhci: convert reset into a library function
Rather than having platform_reset_enter/platform_reset_exit methods,
turn the core of the reset handling into a library function which
platforms can call at the appropriate moment in their (new) reset
method.

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>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-22 07:26:28 -04:00
Russell King 2317f56c05 mmc: sdhci: convert generic bus width setup to library function
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>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>
2014-05-22 07:26:27 -04:00
Laurent Pinchart 214fc309d1 mmc: slot-gpio: Add debouncing capability to mmc_gpio_request_cd()
Add a debounce parameter to the mmc_gpio_request_cd() function that
enables GPIO debouncing when set to a non-zero value. This can be used
by MMC host drivers to enable debouncing on the card detect signal.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-08-24 23:45:09 -04:00
Arnd Bergmann e2f6aac6a8 mmc: sirf: fix sdhci_pltfm_init sequence
Patch "mmc: sdhci: Add size for caller in init+register" changed the
interface for sdhci_pltfm_init, while patch "mmc: sdhci-sirf: add mmc
host sdhci-pltfm based driver for SiRF SoCs" added a new driver
with the old interface.

This changes the sirf driver to use the new interface, avoiding
one warning, and simplifying the init sequence. Since we're here
already, this also adds an error path for failed clk_prepare_enable.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christian Daudt <csd@broadcom.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-06-27 11:17:25 -04:00
Barry Song 0b856f4ecb mmc: sdhci-sirf: let device core setup the default pin configuration
With device core now able to setup the default pin configuration, the
call to devm_pinctrl_get_select_default can be removed. And the pin
configuration code based on the deprecated Samsung specific gpio
bindings is also removed.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-06-27 10:34:17 -04:00
Barry Song b3b665b0a9 mmc: sdhci-sirf: add mmc host sdhci-pltfm based driver for SiRF SoCs
This patch adds the new driver for CSR SiRF SoCs:

SiRFprimaII: unicore ARM Cortex-A9
SiRFatlas6: unicore ARM Cortex-A9
SiRFmarco: dual core ARM Cortex-A9 SMP

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Bin Shi <Bin.Shi@csr.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2013-03-22 13:29:46 -04:00