On 08/08/2014 11:42, Ronald Wahl :
> Commit 7628083227b6bc4a7e33d7c381d7a4e558424b6b (usb: gadget: at91_udc:
> prepare clk before calling enable) added clock preparation in interrupt
> context. This is not allowed as it might sleep. Also setting the clock
> rate is unsafe to call from there for the same reason. Move clock
> preparation and setting clock rate into process context (at91udc_probe).
> 
> Signed-off-by: Ronald Wahl <ronald.w...@raritan.com>

Acked-by: Nicolas Ferre <nicolas.fe...@atmel.com>

> ---
> v3 -> v4:
>     - no code changes
>     - update commit message
>     - add changelog
> 
> v2 -> v3: (NOTE: this patch was also send with the v2 tag)
>     - moved setting the clock rate into process context as well as it may
>       also sleep
>     - update commit message
> 
> v1 -> v2:
>     - no changes (first v2 got out accidently)
> 
>  drivers/usb/gadget/udc/at91_udc.c | 44 
> ++++++++++++++++++++++++++++-----------
>  1 file changed, 32 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/at91_udc.c 
> b/drivers/usb/gadget/udc/at91_udc.c
> index cfd18bc..0d685d0 100644
> --- a/drivers/usb/gadget/udc/at91_udc.c
> +++ b/drivers/usb/gadget/udc/at91_udc.c
> @@ -870,12 +870,10 @@ static void clk_on(struct at91_udc *udc)
>               return;
>       udc->clocked = 1;
>  
> -     if (IS_ENABLED(CONFIG_COMMON_CLK)) {
> -             clk_set_rate(udc->uclk, 48000000);
> -             clk_prepare_enable(udc->uclk);
> -     }
> -     clk_prepare_enable(udc->iclk);
> -     clk_prepare_enable(udc->fclk);
> +     if (IS_ENABLED(CONFIG_COMMON_CLK))
> +             clk_enable(udc->uclk);
> +     clk_enable(udc->iclk);
> +     clk_enable(udc->fclk);
>  }
>  
>  static void clk_off(struct at91_udc *udc)
> @@ -884,10 +882,10 @@ static void clk_off(struct at91_udc *udc)
>               return;
>       udc->clocked = 0;
>       udc->gadget.speed = USB_SPEED_UNKNOWN;
> -     clk_disable_unprepare(udc->fclk);
> -     clk_disable_unprepare(udc->iclk);
> +     clk_disable(udc->fclk);
> +     clk_disable(udc->iclk);
>       if (IS_ENABLED(CONFIG_COMMON_CLK))
> -             clk_disable_unprepare(udc->uclk);
> +             clk_disable(udc->uclk);
>  }
>  
>  /*
> @@ -1780,14 +1778,24 @@ static int at91udc_probe(struct platform_device *pdev)
>       }
>  
>       /* don't do anything until we have both gadget driver and VBUS */
> +     if (IS_ENABLED(CONFIG_COMMON_CLK)) {
> +             clk_set_rate(udc->uclk, 48000000);
> +             retval = clk_prepare(udc->uclk);
> +             if (retval)
> +                     goto fail1;
> +     }
> +     retval = clk_prepare(udc->fclk);
> +     if (retval)
> +             goto fail1a;
> +
>       retval = clk_prepare_enable(udc->iclk);
>       if (retval)
> -             goto fail1;
> +             goto fail1b;
>       at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
>       at91_udp_write(udc, AT91_UDP_IDR, 0xffffffff);
>       /* Clear all pending interrupts - UDP may be used by bootloader. */
>       at91_udp_write(udc, AT91_UDP_ICR, 0xffffffff);
> -     clk_disable_unprepare(udc->iclk);
> +     clk_disable(udc->iclk);
>  
>       /* request UDC and maybe VBUS irqs */
>       udc->udp_irq = platform_get_irq(pdev, 0);
> @@ -1795,7 +1803,7 @@ static int at91udc_probe(struct platform_device *pdev)
>                       0, driver_name, udc);
>       if (retval < 0) {
>               DBG("request irq %d failed\n", udc->udp_irq);
> -             goto fail1;
> +             goto fail1c;
>       }
>       if (gpio_is_valid(udc->board.vbus_pin)) {
>               retval = gpio_request(udc->board.vbus_pin, "udc_vbus");
> @@ -1848,6 +1856,13 @@ fail3:
>               gpio_free(udc->board.vbus_pin);
>  fail2:
>       free_irq(udc->udp_irq, udc);
> +fail1c:
> +     clk_unprepare(udc->iclk);
> +fail1b:
> +     clk_unprepare(udc->fclk);
> +fail1a:
> +     if (IS_ENABLED(CONFIG_COMMON_CLK))
> +             clk_unprepare(udc->uclk);
>  fail1:
>       if (IS_ENABLED(CONFIG_COMMON_CLK) && !IS_ERR(udc->uclk))
>               clk_put(udc->uclk);
> @@ -1896,6 +1911,11 @@ static int __exit at91udc_remove(struct 
> platform_device *pdev)
>       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>       release_mem_region(res->start, resource_size(res));
>  
> +     if (IS_ENABLED(CONFIG_COMMON_CLK))
> +             clk_unprepare(udc->uclk);
> +     clk_unprepare(udc->fclk);
> +     clk_unprepare(udc->iclk);
> +
>       clk_put(udc->iclk);
>       clk_put(udc->fclk);
>       if (IS_ENABLED(CONFIG_COMMON_CLK))
> 


-- 
Nicolas Ferre
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