On 17/01/2015 at 16:36:35 +0100, Sylvain Rochet wrote :
> Disable/unprepare clocks without testing the sleep target_state, removed
> the at91_suspend_entering_slow_clock() call (which is only a
> target_state == PM_SUSPEND_MEM).
>
> Other kind of suspend now benefit from the power save induced by this
> PLL deactivation. The resume penalty is about 500 us, which is not
> negligible but acceptable considering the amount of power we are saving.
>
> Signed-off-by: Sylvain Rochet <sylvain.roc...@finsecur.com>
> Reported-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.bell...@free-electrons.com>
> ---
> drivers/usb/host/ohci-at91.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
> index dc9e4e6..f0da734 100644
> --- a/drivers/usb/host/ohci-at91.c
> +++ b/drivers/usb/host/ohci-at91.c
> @@ -49,6 +49,8 @@ extern int usb_disabled(void);
>
> static void at91_start_clock(void)
> {
> + if (clocked)
> + return;
> if (IS_ENABLED(CONFIG_COMMON_CLK)) {
> clk_set_rate(uclk, 48000000);
> clk_prepare_enable(uclk);
> @@ -61,6 +63,8 @@ static void at91_start_clock(void)
>
> static void at91_stop_clock(void)
> {
> + if (!clocked)
> + return;
> clk_disable_unprepare(fclk);
> clk_disable_unprepare(iclk);
> clk_disable_unprepare(hclk);
> @@ -615,16 +619,14 @@ ohci_hcd_at91_drv_suspend(struct platform_device *pdev,
> pm_message_t mesg)
> *
> * REVISIT: some boards will be able to turn VBUS off...
> */
> - if (at91_suspend_entering_slow_clock()) {
> - ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
> - ohci->hc_control &= OHCI_CTRL_RWC;
> - ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
> - ohci->rh_state = OHCI_RH_HALTED;
> -
> - /* flush the writes */
> - (void) ohci_readl (ohci, &ohci->regs->control);
> - at91_stop_clock();
> - }
> + ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
> + ohci->hc_control &= OHCI_CTRL_RWC;
> + ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
> + ohci->rh_state = OHCI_RH_HALTED;
> +
> + /* flush the writes */
> + (void) ohci_readl (ohci, &ohci->regs->control);
> + at91_stop_clock();
>
> return ret;
> }
> @@ -636,8 +638,7 @@ static int ohci_hcd_at91_drv_resume(struct
> platform_device *pdev)
> if (device_may_wakeup(&pdev->dev))
> disable_irq_wake(hcd->irq);
>
> - if (!clocked)
> - at91_start_clock();
> + at91_start_clock();
>
> ohci_resume(hcd, false);
> return 0;
> --
> 2.1.4
>
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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