On Wed, 18 Jun 2014, Doug Anderson wrote:
> From: Andrew Bresticker <abres...@chromium.org>
>
> If we receive EC interrupts after the cros_ec driver has probed, but
> before the cros_ec_keyb driver has probed, the cros_ec IRQ handler
> will not run the cros_ec_keyb notifier and the EC will leave the IRQ
> line asserted. The cros_ec IRQ handler then returns IRQ_HANDLED and
> the resulting flood of interrupts causes the machine to hang.
>
> Since the EC interrupt is currently only used for the keyboard, move
> the setup and handling of the EC interrupt to the cros_ec_keyb driver.
>
> Signed-off-by: Andrew Bresticker <abres...@chromium.org>
> Signed-off-by: Doug Anderson <diand...@chromium.org>
> ---
> Changes in v2:
> - IRQs should be optional => move EC interrupt to keyboard.
>
> drivers/input/keyboard/cros_ec_keyb.c | 58
> ++++++++++++++++++++---------------
> drivers/mfd/cros_ec.c | 35 +--------------------
> include/linux/mfd/cros_ec.h | 2 --
> 3 files changed, 34 insertions(+), 61 deletions(-)
For the MFD changes:
Acked-by: Lee Jones <lee.jo...@linaro.org>
> diff --git a/drivers/input/keyboard/cros_ec_keyb.c
> b/drivers/input/keyboard/cros_ec_keyb.c
> index b8341ab..791781a 100644
> --- a/drivers/input/keyboard/cros_ec_keyb.c
> +++ b/drivers/input/keyboard/cros_ec_keyb.c
> @@ -24,8 +24,8 @@
> #include <linux/module.h>
> #include <linux/i2c.h>
> #include <linux/input.h>
> +#include <linux/interrupt.h>
> #include <linux/kernel.h>
> -#include <linux/notifier.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
> #include <linux/input/matrix_keypad.h>
> @@ -42,7 +42,6 @@
> * @dev: Device pointer
> * @idev: Input device
> * @ec: Top level ChromeOS device to use to talk to EC
> - * @event_notifier: interrupt event notifier for transport devices
> */
> struct cros_ec_keyb {
> unsigned int rows;
> @@ -55,7 +54,6 @@ struct cros_ec_keyb {
> struct device *dev;
> struct input_dev *idev;
> struct cros_ec_device *ec;
> - struct notifier_block notifier;
> };
>
>
> @@ -173,22 +171,6 @@ static void cros_ec_keyb_process(struct cros_ec_keyb
> *ckdev,
> input_sync(ckdev->idev);
> }
>
> -static int cros_ec_keyb_open(struct input_dev *dev)
> -{
> - struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> -
> - return blocking_notifier_chain_register(&ckdev->ec->event_notifier,
> - &ckdev->notifier);
> -}
> -
> -static void cros_ec_keyb_close(struct input_dev *dev)
> -{
> - struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> -
> - blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
> - &ckdev->notifier);
> -}
> -
> static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t
> *kb_state)
> {
> struct cros_ec_command msg = {
> @@ -203,19 +185,41 @@ static int cros_ec_keyb_get_state(struct cros_ec_keyb
> *ckdev, uint8_t *kb_state)
> return ckdev->ec->cmd_xfer(ckdev->ec, &msg);
> }
>
> -static int cros_ec_keyb_work(struct notifier_block *nb,
> - unsigned long state, void *_notify)
> +static irqreturn_t cros_ec_keyb_irq(int irq, void *data)
> {
> + struct cros_ec_keyb *ckdev = data;
> + struct cros_ec_device *ec = ckdev->ec;
> int ret;
> - struct cros_ec_keyb *ckdev = container_of(nb, struct cros_ec_keyb,
> - notifier);
> uint8_t kb_state[ckdev->cols];
>
> + if (device_may_wakeup(ec->dev))
> + pm_wakeup_event(ec->dev, 0);
> +
> ret = cros_ec_keyb_get_state(ckdev, kb_state);
> if (ret >= 0)
> cros_ec_keyb_process(ckdev, kb_state, ret);
> + else
> + dev_err(ec->dev, "failed to get keyboard state: %d\n", ret);
>
> - return NOTIFY_DONE;
> + return IRQ_HANDLED;
> +}
> +
> +static int cros_ec_keyb_open(struct input_dev *dev)
> +{
> + struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> + struct cros_ec_device *ec = ckdev->ec;
> +
> + return request_threaded_irq(ec->irq, NULL, cros_ec_keyb_irq,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + "cros_ec_keyb", ckdev);
> +}
> +
> +static void cros_ec_keyb_close(struct input_dev *dev)
> +{
> + struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> + struct cros_ec_device *ec = ckdev->ec;
> +
> + free_irq(ec->irq, ckdev);
> }
>
> static int cros_ec_keyb_probe(struct platform_device *pdev)
> @@ -246,8 +250,12 @@ static int cros_ec_keyb_probe(struct platform_device
> *pdev)
> if (!idev)
> return -ENOMEM;
>
> + if (!ec->irq) {
> + dev_err(dev, "no EC IRQ specified\n");
> + return -EINVAL;
> + }
> +
> ckdev->ec = ec;
> - ckdev->notifier.notifier_call = cros_ec_keyb_work;
> ckdev->dev = dev;
> dev_set_drvdata(&pdev->dev, ckdev);
>
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 83e30c6..4873f9c 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -62,18 +62,6 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
> }
> EXPORT_SYMBOL(cros_ec_check_result);
>
> -static irqreturn_t ec_irq_thread(int irq, void *data)
> -{
> - struct cros_ec_device *ec_dev = data;
> -
> - if (device_may_wakeup(ec_dev->dev))
> - pm_wakeup_event(ec_dev->dev, 0);
> -
> - blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);
> -
> - return IRQ_HANDLED;
> -}
> -
> static const struct mfd_cell cros_devs[] = {
> {
> .name = "cros-ec-keyb",
> @@ -92,8 +80,6 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> struct device *dev = ec_dev->dev;
> int err = 0;
>
> - BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
> -
> if (ec_dev->din_size) {
> ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
> if (!ec_dev->din)
> @@ -105,42 +91,23 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> return -ENOMEM;
> }
>
> - if (!ec_dev->irq) {
> - dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
> - return err;
> - }
> -
> - err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
> - IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> - "chromeos-ec", ec_dev);
> - if (err) {
> - dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
> - return err;
> - }
> -
> err = mfd_add_devices(dev, 0, cros_devs,
> ARRAY_SIZE(cros_devs),
> NULL, ec_dev->irq, NULL);
> if (err) {
> dev_err(dev, "failed to add mfd devices\n");
> - goto fail_mfd;
> + return err;
> }
>
> dev_info(dev, "Chrome EC device registered\n");
>
> return 0;
> -
> -fail_mfd:
> - free_irq(ec_dev->irq, ec_dev);
> -
> - return err;
> }
> EXPORT_SYMBOL(cros_ec_register);
>
> int cros_ec_remove(struct cros_ec_device *ec_dev)
> {
> mfd_remove_devices(ec_dev->dev);
> - free_irq(ec_dev->irq, ec_dev);
>
> return 0;
> }
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 0ebf26f..fcbe9d1 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -62,7 +62,6 @@ struct cros_ec_command {
> * @dev: Device pointer
> * @was_wake_device: true if this device was set to wake the system from
> * sleep at the last suspend
> - * @event_notifier: interrupt event notifier for transport devices
> * @cmd_xfer: send command to EC and get response
> * Returns the number of bytes received if the communication succeeded,
> but
> * that doesn't mean the EC was happy with the command. The caller
> @@ -93,7 +92,6 @@ struct cros_ec_device {
> struct device *dev;
> bool was_wake_device;
> struct class *cros_class;
> - struct blocking_notifier_head event_notifier;
> int (*cmd_xfer)(struct cros_ec_device *ec,
> struct cros_ec_command *msg);
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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