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SubjectRe: [PATCH 2/2] mfd: rtsx_usb: Defer autosuspend while card exists
On Thu, 15 Jan 2015, Roger Tseng wrote:

> A card insertion happens after the lastest polling before reader is
> suspended may never have a chance to be detected. Under current 1-HZ
> polling interval setting in mmc_core, the worst case of such
> undetectablility is about 1 second.
>
> To further reduce the undetectability, detect card slot again in suspend
> method and defer the autosuspend if the slot is loaded. The default 2
> second autosuspend delay of USB subsystem should let the next polling
> detects the card.
>
> Signed-off-by: Roger Tseng <rogerable@realtek.com>
> ---
> drivers/mfd/rtsx_usb.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)

Applied, thanks.

> diff --git a/drivers/mfd/rtsx_usb.c b/drivers/mfd/rtsx_usb.c
> index 076694126e5d..63883fd025c0 100644
> --- a/drivers/mfd/rtsx_usb.c
> +++ b/drivers/mfd/rtsx_usb.c
> @@ -687,6 +687,20 @@ static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
> dev_dbg(&intf->dev, "%s called with pm message 0x%04x\n",
> __func__, message.event);
>
> + if (PMSG_IS_AUTO(message)) {
> + if (mutex_trylock(&ucr->dev_mutex)) {
> + rtsx_usb_get_card_status(ucr, &val);
> + mutex_unlock(&ucr->dev_mutex);
> +
> + /* Defer the autosuspend if card exists */
> + if (val & (SD_CD | MS_CD))
> + return -EAGAIN;
> + } else {
> + /* There is an ongoing operation*/
> + return -EAGAIN;
> + }
> + }
> +
> return 0;
> }
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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