Hi,
On Mon, Oct 15, 2012 at 04:49:58PM -0700, Kevin Hilman wrote:
> From: Kevin Hilman <khilman@xxxxxx>
>
> The runtime PM framework assumes that the hardware state of devices
> when initialized is disabled. For all omap_devices, we idle/disable
> device by default. However, the console uart uses a "no idle" option
> during omap_device init in order to allow earlyprintk usage to work
> seamlessly during boot.
>
> Because the hardware is left partially enabled after init (whatever
> the bootloader settings were), the omap_device should later be fully
> initialized (including mux) and the runtime PM framework should be
> told that the device is active, and not disabled so that the hardware
> state is in sync with runtime PM state.
>
> To fix, after the device has been created/registered, call
> omap_device_enable() to finialize init and use pm_runtime_set_active()
> to tell the runtime PM core the device is enabled.
>
> Tested on 2420/n810, 3530/Overo, 3530/Beagle, 3730/OveroSTORM,
> 3730/Beagle-xM, 4460/PandaES.
>
> Reported-by: Paul Walmsley <paul@xxxxxxxxx>
> Suggested-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Cc: Sourav Poddar <sourav.poddar@xxxxxx>
> Signed-off-by: Kevin Hilman <khilman@xxxxxx>
> ---
> Applies against v3.7-rc1.
> Fix targetted for v3.7.
>
> I'm still not entirely sure why this has worked up to now on OMAP3/4
> but not on OMAP2. Even so, this fix is needed for all platforms to
> ensure matching hardware state and runtime PM state.
>
> arch/arm/mach-omap2/serial.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> index 0405c81..37b5dbe 100644
> --- a/arch/arm/mach-omap2/serial.c
> +++ b/arch/arm/mach-omap2/serial.c
> @@ -327,6 +327,11 @@ void __init omap_serial_init_port(struct omap_board_data *bdata,
> if ((console_uart_id == bdata->id) && no_console_suspend)
> omap_device_disable_idle_on_suspend(pdev);
>
> + if (console_uart_id == bdata->id) {
> + omap_device_enable(pdev);
> + pm_runtime_set_active(&pdev->dev);
> + }
> +
> oh->mux = omap_hwmod_mux_init(bdata->pads, bdata->pads_cnt);
>
> oh->dev_attr = uart;
looks good to me. Even took care of doing that only for the console
UART.
Reviewed-by: Felipe Balbi <balbi@xxxxxx>
sorry for the issues caused.
--
balbi
Attachment:
signature.asc
Description: Digital signature
