This is a note to let you know that I've just added the patch titled
usb: gadget: at91_udc: move prepare clk into process context
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From b2ba27a5c56ff7204d8a8684893d64d4afe2cee5 Mon Sep 17 00:00:00 2001
From: Ronald Wahl <ronald.wahl@xxxxxxxxxxx>
Date: Wed, 19 Nov 2014 16:37:27 +0100
Subject: usb: gadget: at91_udc: move prepare clk into process context
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.wahl@xxxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v3.17+
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
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 fe0534c0e3d4..eb2999c5d03c 100644
--- a/drivers/usb/gadget/udc/at91_udc.c
+++ b/drivers/usb/gadget/udc/at91_udc.c
@@ -895,12 +895,10 @@ 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)
@@ -909,10 +907,10 @@ 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);
}
/*
@@ -1793,14 +1791,24 @@ 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);
@@ -1808,7 +1816,7 @@ 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");
@@ -1861,6 +1869,13 @@ 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);
@@ -1909,6 +1924,11 @@ 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))
--
2.1.3
--
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