I noticed that when debugging some USB clocking issue that there weren't
many ways to tell what the state of the USB clocking system was. This
adds a few logging statements to see what the relevant code is trying to
do.
Signed-off-by: Marcin Ziemianowicz <[email protected]>
---
drivers/clk/at91/clk-pll.c | 6 +++++-
drivers/clk/at91/clk-usb.c | 10 ++++++++--
drivers/usb/host/ohci-at91.c | 21 +++++++++++++++------
3 files changed, 28 insertions(+), 9 deletions(-)
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c
index 7d3223fc7161..534961766ae5 100644
--- a/drivers/clk/at91/clk-pll.c
+++ b/drivers/clk/at91/clk-pll.c
@@ -133,6 +133,7 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
{
struct clk_pll *pll = to_clk_pll(hw);
unsigned int pllr;
+ unsigned long recalcedrate;
u16 mul;
u8 div;
@@ -144,7 +145,10 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
if (!div || !mul)
return 0;
- return (parent_rate / div) * (mul + 1);
+ recalcedrate = (parent_rate / div) * (mul + 1);
+ pr_debug("clk-pll: calculating new rate, (%lu hz / %u) * %u = %lu hz\n",
+ parent_rate, div, mul, recalcedrate);
+ return recalcedrate;
}
static long clk_pll_get_best_div_mul(struct clk_pll *pll, unsigned long rate,
diff --git a/drivers/clk/at91/clk-usb.c b/drivers/clk/at91/clk-usb.c
index 791770a563fc..2fa877e99bac 100644
--- a/drivers/clk/at91/clk-usb.c
+++ b/drivers/clk/at91/clk-usb.c
@@ -48,11 +48,15 @@ static unsigned long at91sam9x5_clk_usb_recalc_rate(struct clk_hw *hw,
struct at91sam9x5_clk_usb *usb = to_at91sam9x5_clk_usb(hw);
unsigned int usbr;
u8 usbdiv;
+ unsigned int calcdclock;
regmap_read(usb->regmap, AT91_PMC_USB, &usbr);
usbdiv = (usbr & AT91_PMC_OHCIUSBDIV) >> SAM9X5_USB_DIV_SHIFT;
- return DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
+ calcdclock = DIV_ROUND_CLOSEST(parent_rate, (usbdiv + 1));
+ pr_debug("clk-usb: calculating new rate, %lu hz / %u = %u hz\n",
+ parent_rate, usbdiv + 1, calcdclock);
+ return calcdclock;
}
static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
@@ -98,7 +102,6 @@ static int at91sam9x5_clk_usb_determine_rate(struct clk_hw *hw,
if (!best_diff)
break;
}
-
if (best_rate < 0)
return best_rate;
@@ -142,6 +145,9 @@ static int at91sam9x5_clk_usb_set_rate(struct clk_hw *hw, unsigned long rate,
if (div > SAM9X5_USB_MAX_DIV + 1 || !div)
return -EINVAL;
+ pr_debug("clk-usb: setting USB clock divider to %lu hz / %lu = %lu hz\n",
+ parent_rate, div, rate);
+
regmap_update_bits(usb->regmap, AT91_PMC_USB, AT91_PMC_OHCIUSBDIV,
(div - 1) << SAM9X5_USB_DIV_SHIFT);
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 5ad9e9bdc8ee..5dfc4e464cfe 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -70,11 +70,12 @@ static const struct ohci_driver_overrides ohci_at91_drv_overrides __initconst =
/*-------------------------------------------------------------------------*/
-static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
+static void at91_start_clock(struct ohci_at91_priv *ohci_at91, struct device *dev)
{
if (ohci_at91->clocked)
return;
+ dev_dbg(dev, "Enabling hclk, iclk, and setting fclk to 48 Mhz\n");
clk_set_rate(ohci_at91->fclk, 48000000);
clk_prepare_enable(ohci_at91->hclk);
clk_prepare_enable(ohci_at91->iclk);
@@ -82,11 +83,12 @@ static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
ohci_at91->clocked = true;
}
-static void at91_stop_clock(struct ohci_at91_priv *ohci_at91)
+static void at91_stop_clock(struct ohci_at91_priv *ohci_at91, struct device *dev)
{
if (!ohci_at91->clocked)
return;
+ dev_dbg(dev, "Disabling hclk, iclk, and fclk\n");
clk_disable_unprepare(ohci_at91->fclk);
clk_disable_unprepare(ohci_at91->iclk);
clk_disable_unprepare(ohci_at91->hclk);
@@ -104,12 +106,19 @@ static void at91_start_hc(struct platform_device *pdev)
/*
* Start the USB clocks.
*/
- at91_start_clock(ohci_at91);
+ at91_start_clock(ohci_at91, &pdev->dev);
/*
* The USB host controller must remain in reset.
*/
writel(0, ®s->control);
+
+ /*
+ * Say what the clocks are set to.
+ */
+ dev_dbg(&pdev->dev, "hclk set to: %lu hz\n", clk_get_rate(ohci_at91->hclk));
+ dev_dbg(&pdev->dev, "iclk set to: %lu hz\n", clk_get_rate(ohci_at91->iclk));
+ dev_dbg(&pdev->dev, "fclk set to: %lu hz\n", clk_get_rate(ohci_at91->fclk));
}
static void at91_stop_hc(struct platform_device *pdev)
@@ -128,7 +137,7 @@ static void at91_stop_hc(struct platform_device *pdev)
/*
* Stop the USB clocks.
*/
- at91_stop_clock(ohci_at91);
+ at91_stop_clock(ohci_at91, &pdev->dev);
}
@@ -623,7 +632,7 @@ ohci_hcd_at91_drv_suspend(struct device *dev)
/* flush the writes */
(void) ohci_readl (ohci, &ohci->regs->control);
- at91_stop_clock(ohci_at91);
+ at91_stop_clock(ohci_at91, dev);
}
return ret;
@@ -638,7 +647,7 @@ ohci_hcd_at91_drv_resume(struct device *dev)
if (ohci_at91->wakeup)
disable_irq_wake(hcd->irq);
- at91_start_clock(ohci_at91);
+ at91_start_clock(ohci_at91, dev);
ohci_resume(hcd, false);
--
2.16.3
On Sun, Apr 08, 2018 at 05:43:30AM -0400, Marcin wrote:
> I noticed that when debugging some USB clocking issue that there weren't
> many ways to tell what the state of the USB clocking system was. This
> adds a few logging statements to see what the relevant code is trying to
> do.
>
> Signed-off-by: Marcin Ziemianowicz <[email protected]>
Your "From:" line doesn't match this name :(
On Sun, Apr 08, 2018 at 11:54:49AM +0200, Greg Kroah-Hartman wrote:
> On Sun, Apr 08, 2018 at 05:43:30AM -0400, Marcin wrote:
> > I noticed that when debugging some USB clocking issue that there weren't
> > many ways to tell what the state of the USB clocking system was. This
> > adds a few logging statements to see what the relevant code is trying to
> > do.
> >
> > Signed-off-by: Marcin Ziemianowicz <[email protected]>
>
> Your "From:" line doesn't match this name :(
Ah drat, I knew I did something wrong. You suggested in IRC that I wait a day
for others to reply, so after that I will attempt to version my patchset.
On Sun, 8 Apr 2018, Marcin wrote:
> I noticed that when debugging some USB clocking issue that there weren't
> many ways to tell what the state of the USB clocking system was. This
> adds a few logging statements to see what the relevant code is trying to
> do.
>
> Signed-off-by: Marcin Ziemianowicz <[email protected]>
It seems like you have added more debugging lines than necessary.
> --- a/drivers/usb/host/ohci-at91.c
> +++ b/drivers/usb/host/ohci-at91.c
> @@ -70,11 +70,12 @@ static const struct ohci_driver_overrides ohci_at91_drv_overrides __initconst =
>
> /*-------------------------------------------------------------------------*/
>
> -static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
> +static void at91_start_clock(struct ohci_at91_priv *ohci_at91, struct device *dev)
> {
> if (ohci_at91->clocked)
> return;
>
> + dev_dbg(dev, "Enabling hclk, iclk, and setting fclk to 48 Mhz\n");
Here you list all the clocks and give one frequency.
> clk_set_rate(ohci_at91->fclk, 48000000);
> clk_prepare_enable(ohci_at91->hclk);
> clk_prepare_enable(ohci_at91->iclk);
> @@ -104,12 +106,19 @@ static void at91_start_hc(struct platform_device *pdev)
> /*
> * Start the USB clocks.
> */
> - at91_start_clock(ohci_at91);
> + at91_start_clock(ohci_at91, &pdev->dev);
>
> /*
> * The USB host controller must remain in reset.
> */
> writel(0, ®s->control);
> +
> + /*
> + * Say what the clocks are set to.
> + */
> + dev_dbg(&pdev->dev, "hclk set to: %lu hz\n", clk_get_rate(ohci_at91->hclk));
> + dev_dbg(&pdev->dev, "iclk set to: %lu hz\n", clk_get_rate(ohci_at91->iclk));
> + dev_dbg(&pdev->dev, "fclk set to: %lu hz\n", clk_get_rate(ohci_at91->fclk));
Here you list all the clocks a second time and give all the
frequencies.
> }
>
> static void at91_stop_hc(struct platform_device *pdev)
Alan Stern