clk: clk-twl6040: Fix imprecise external abort for pdmclk
diff mbox series

Message ID 20190211225907.38511-1-tony@atomide.com
State New
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  • clk: clk-twl6040: Fix imprecise external abort for pdmclk
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Commit Message

Tony Lindgren Feb. 11, 2019, 10:59 p.m. UTC
I noticed that modprobe clk-twl6040 can fail after a cold boot with:
abe_cm:clk:0010:0: failed to enable
...
Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20

WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
...
(clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
(_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
(_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
(omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
(sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
(__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
(rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
(rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
(__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
(sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)

After searching around for a similar issue, I came across an earlier fix
that never got merged upstream in the Android tree for glass-omap-xrr02.
There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
by Misael Lopez Cruz <misael.lopez@ti.com>.

Based on my observations, this fix is also needed when cold booting
devices, and not just for deeper idle modes. Since we now have a clock
driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().

Cc: Misael Lopez Cruz <misael.lopez@ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/clk/clk-twl6040.c | 53 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 51 insertions(+), 2 deletions(-)

Comments

Peter Ujfalusi Feb. 12, 2019, 11:07 a.m. UTC | #1
On 12/02/2019 0.59, Tony Lindgren wrote:
> I noticed that modprobe clk-twl6040 can fail after a cold boot with:
> abe_cm:clk:0010:0: failed to enable
> ...
> Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20
> 
> WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
> ...
> (clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
> (_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
> (_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
> (omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
> (sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
> (__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
> (rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
> (rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
> (__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
> (sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)
> 
> After searching around for a similar issue, I came across an earlier fix
> that never got merged upstream in the Android tree for glass-omap-xrr02.
> There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
> by Misael Lopez Cruz <misael.lopez@ti.com>.
> 
> Based on my observations, this fix is also needed when cold booting
> devices, and not just for deeper idle modes. Since we now have a clock
> driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().

Thanks for figuring it out! I came across this patch a while ago and not
sure why I did not ported it.

Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>

> Cc: Misael Lopez Cruz <misael.lopez@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/clk/clk-twl6040.c | 53 +++++++++++++++++++++++++++++++++++++--
>  1 file changed, 51 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/clk-twl6040.c b/drivers/clk/clk-twl6040.c
> --- a/drivers/clk/clk-twl6040.c
> +++ b/drivers/clk/clk-twl6040.c
> @@ -41,6 +41,43 @@ static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
>  	return pdmclk->enabled;
>  }
>  
> +static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,
> +					  unsigned int reg)
> +{
> +	const u8 reset_mask = TWL6040_HPLLRST;	/* Same for HPPLL and LPPLL */
> +	int ret;
> +
> +	ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +/*
> + * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At
> + * Cold Temperature". This affects cold boot and deeper idle states it
> + * seems. The workaround consists of resetting HPPLL and LPPLL.
> + */
> +static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)
> +{
> +	int ret;
> +
> +	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);
> +	if (ret)
> +		return ret;
> +
> +	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int twl6040_pdmclk_prepare(struct clk_hw *hw)
>  {
>  	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
> @@ -48,8 +85,20 @@ static int twl6040_pdmclk_prepare(struct clk_hw *hw)
>  	int ret;
>  
>  	ret = twl6040_power(pdmclk->twl6040, 1);
> -	if (!ret)
> -		pdmclk->enabled = 1;
> +	if (ret)
> +		return ret;
> +
> +	ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);
> +	if (ret)
> +		goto out_err;
> +
> +	pdmclk->enabled = 1;
> +
> +	return 0;
> +
> +out_err:
> +	dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);
> +	twl6040_power(pdmclk->twl6040, 0);
>  
>  	return ret;
>  }
> 

- P├ęter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
Stephen Boyd Feb. 13, 2019, 5:52 p.m. UTC | #2
Quoting Tony Lindgren (2019-02-11 14:59:07)
> I noticed that modprobe clk-twl6040 can fail after a cold boot with:
> abe_cm:clk:0010:0: failed to enable
> ...
> Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20
> 
> WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
> ...
> (clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
> (_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
> (_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
> (omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
> (sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
> (__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
> (rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
> (rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
> (__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
> (sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)
> 
> After searching around for a similar issue, I came across an earlier fix
> that never got merged upstream in the Android tree for glass-omap-xrr02.
> There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
> by Misael Lopez Cruz <misael.lopez@ti.com>.
> 
> Based on my observations, this fix is also needed when cold booting
> devices, and not just for deeper idle modes. Since we now have a clock
> driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().
> 
> Cc: Misael Lopez Cruz <misael.lopez@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>

Should this be backported to stable trees?
Tony Lindgren Feb. 13, 2019, 5:59 p.m. UTC | #3
* Stephen Boyd <sboyd@kernel.org> [190213 17:52]:
> Quoting Tony Lindgren (2019-02-11 14:59:07)
> > I noticed that modprobe clk-twl6040 can fail after a cold boot with:
> > abe_cm:clk:0010:0: failed to enable
> > ...
> > Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20
> > 
> > WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
> > ...
> > (clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
> > (_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
> > (_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
> > (omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
> > (sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
> > (__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
> > (rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
> > (rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
> > (__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
> > (sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)
> > 
> > After searching around for a similar issue, I came across an earlier fix
> > that never got merged upstream in the Android tree for glass-omap-xrr02.
> > There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
> > by Misael Lopez Cruz <misael.lopez@ti.com>.
> > 
> > Based on my observations, this fix is also needed when cold booting
> > devices, and not just for deeper idle modes. Since we now have a clock
> > driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().
> > 
> > Cc: Misael Lopez Cruz <misael.lopez@ti.com>
> > Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> > Signed-off-by: Tony Lindgren <tony@atomide.com>
> 
> Should this be backported to stable trees?

Yes please, I think that's a good idea.

Regards,

Tony
Stephen Boyd Feb. 21, 2019, 10:11 p.m. UTC | #4
Quoting Tony Lindgren (2019-02-11 14:59:07)
> I noticed that modprobe clk-twl6040 can fail after a cold boot with:
> abe_cm:clk:0010:0: failed to enable
> ...
> Unhandled fault: imprecise external abort (0x1406) at 0xbe896b20
> 
> WARNING: CPU: 1 PID: 29 at drivers/clk/clk.c:828 clk_core_disable_lock+0x18/0x24
> ...
> (clk_core_disable_lock) from [<c0123534>] (_disable_clocks+0x18/0x90)
> (_disable_clocks) from [<c0124040>] (_idle+0x17c/0x244)
> (_idle) from [<c0125ad4>] (omap_hwmod_idle+0x24/0x44)
> (omap_hwmod_idle) from [<c053a038>] (sysc_runtime_suspend+0x48/0x108)
> (sysc_runtime_suspend) from [<c06084c4>] (__rpm_callback+0x144/0x1d8)
> (__rpm_callback) from [<c0608578>] (rpm_callback+0x20/0x80)
> (rpm_callback) from [<c0607034>] (rpm_suspend+0x120/0x694)
> (rpm_suspend) from [<c0607a78>] (__pm_runtime_idle+0x60/0x84)
> (__pm_runtime_idle) from [<c053aaf0>] (sysc_probe+0x874/0xf2c)
> (sysc_probe) from [<c05fecd4>] (platform_drv_probe+0x48/0x98)
> 
> After searching around for a similar issue, I came across an earlier fix
> that never got merged upstream in the Android tree for glass-omap-xrr02.
> There is patch "MFD: twl6040-codec: Implement PDMCLK cold temp errata"
> by Misael Lopez Cruz <misael.lopez@ti.com>.
> 
> Based on my observations, this fix is also needed when cold booting
> devices, and not just for deeper idle modes. Since we now have a clock
> driver for pdmclk, let's fix the issue in twl6040_pdmclk_prepare().
> 
> Cc: Misael Lopez Cruz <misael.lopez@ti.com>
> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---

Applied to clk-next + added a stable tag

Patch
diff mbox series

diff --git a/drivers/clk/clk-twl6040.c b/drivers/clk/clk-twl6040.c
--- a/drivers/clk/clk-twl6040.c
+++ b/drivers/clk/clk-twl6040.c
@@ -41,6 +41,43 @@  static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
 	return pdmclk->enabled;
 }
 
+static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,
+					  unsigned int reg)
+{
+	const u8 reset_mask = TWL6040_HPLLRST;	/* Same for HPPLL and LPPLL */
+	int ret;
+
+	ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);
+	if (ret < 0)
+		return ret;
+
+	ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At
+ * Cold Temperature". This affects cold boot and deeper idle states it
+ * seems. The workaround consists of resetting HPPLL and LPPLL.
+ */
+static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)
+{
+	int ret;
+
+	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);
+	if (ret)
+		return ret;
+
+	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 static int twl6040_pdmclk_prepare(struct clk_hw *hw)
 {
 	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
@@ -48,8 +85,20 @@  static int twl6040_pdmclk_prepare(struct clk_hw *hw)
 	int ret;
 
 	ret = twl6040_power(pdmclk->twl6040, 1);
-	if (!ret)
-		pdmclk->enabled = 1;
+	if (ret)
+		return ret;
+
+	ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);
+	if (ret)
+		goto out_err;
+
+	pdmclk->enabled = 1;
+
+	return 0;
+
+out_err:
+	dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);
+	twl6040_power(pdmclk->twl6040, 0);
 
 	return ret;
 }