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SubjectRe: [PATCH 2/2] extcon: Fix extcon_cable_get_state() from getting old state after notification
Hi Roger,

On 07/06/2015 11:46 PM, Roger Quadros wrote:
> Currently the extcon code notifiers the interested listeners
> before it updates the extcon state with the new state.
> This will cause the listeners that use extcon_cable_get_state()
> to get the stale state and loose the new state.
>
> Fix this by first changing the extcon state variable and then
> notifying listeners.
>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
> drivers/extcon/extcon.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)

Applied it.

Thanks,
Chanwoo Choi

>
> diff --git a/drivers/extcon/extcon.c b/drivers/extcon/extcon.c
> index 868c6e2..26d1e1e 100644
> --- a/drivers/extcon/extcon.c
> +++ b/drivers/extcon/extcon.c
> @@ -275,19 +275,25 @@ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state)
> spin_lock_irqsave(&edev->lock, flags);
>
> if (edev->state != ((edev->state & ~mask) | (state & mask))) {
> + u32 old_state;
> +
> if (check_mutually_exclusive(edev, (edev->state & ~mask) |
> (state & mask))) {
> spin_unlock_irqrestore(&edev->lock, flags);
> return -EPERM;
> }
>
> + old_state = edev->state;
> + edev->state &= ~mask;
> + edev->state |= state & mask;
> +
> for (index = 0; index < edev->max_supported; index++) {
> - if (is_extcon_changed(edev->state, state, index, &attached))
> - raw_notifier_call_chain(&edev->nh[index], attached, edev);
> + if (is_extcon_changed(old_state, edev->state, index,
> + &attached))
> + raw_notifier_call_chain(&edev->nh[index],
> + attached, edev);
> }
>
> - edev->state &= ~mask;
> - edev->state |= state & mask;
>
> /* This could be in interrupt handler */
> prop_buf = (char *)get_zeroed_page(GFP_ATOMIC);
>



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