[PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[Roger Quadros]

Hi,

This is a follow up solution to the original series in [1]

The first patch fixes the OMAP4 Panda USB detection problems on 3.13-rc1
with u-boot v2013.10.

The remaining 2 patches are required if SOFTRESET needs to be done for the
USB Host module on OMAP3 platforms.

Patch 2 fixes the hwmod RESET logic to prevent multiple SOFTRESETs
being issued to the modules. This multiple SOFTRESET was causing problems
with OMAP3 USB Host module. On Beagleboard C4 this is seen as failure to
mount NFS root over external USB to Ethernet device.

This might be the reason why HWMOD_INIT_NO_RESET was used for the OMAP
USB host module in OMAP3 hwmod data and just carried forward in OMAP4
and OMAP5 hwmod data as well.

cheers,
-roger

[1] - http://thread.gmane.org/gmane.linux.kernel/1603931

Roger Quadros (3):
  ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module
  ARM: OMAP2+: hwmod: Fix RESET logic
  ARM: OMAP3: hwmod data: Don't prevent RESET of USB Host module

 arch/arm/mach-omap2/omap_hwmod.c           | 43 +++++++++++++++++++++++++++++-
 arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 13 +++------
 arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 12 ++-------
 arch/arm/mach-omap2/omap_hwmod_54xx_data.c | 13 +++------
 4 files changed, 50 insertions(+), 31 deletions(-)

-- 
1.8.3.2

[PATCH 1/3] ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module

[Roger Quadros]

Without this, the USB devices are sometimes not detected on OMAP4 Panda
with u-boot v2013.10.

Unlike what the comment states, errata i660 does not state that we
can't RESET the USB host module. Instead it states that RESET is the
only way to recover from a deadlock situation.

RESET ensures that the module is in a known good state irrespective
of what bootloader does with the module, so it must be done at boot.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 12 ++----------
 arch/arm/mach-omap2/omap_hwmod_54xx_data.c | 13 +++----------
 2 files changed, 5 insertions(+), 20 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
index 1e5b12c..3318cae9 100644
--- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
@@ -2937,7 +2937,7 @@ static struct omap_hwmod_class_sysconfig omap44xx_usb_host_hs_sysc = {
 	.sysc_offs	= 0x0010,
 	.syss_offs	= 0x0014,
 	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_SIDLEMODE |
-			   SYSC_HAS_SOFTRESET),
+			   SYSC_HAS_SOFTRESET | SYSC_HAS_RESET_STATUS),
 	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
 			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
 			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
@@ -3001,15 +3001,7 @@ static struct omap_hwmod omap44xx_usb_host_hs_hwmod = {
 	 * hence HWMOD_SWSUP_MSTANDBY
 	 */
 
-	/*
-	 * During system boot; If the hwmod framework resets the module
-	 * the module will have smart idle settings; which can lead to deadlock
-	 * (above Errata Id:i660); so, dont reset the module during boot;
-	 * Use HWMOD_INIT_NO_RESET.
-	 */
-
-	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
-			  HWMOD_INIT_NO_RESET,
+	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
 };
 
 /*
diff --git a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
index 9e08d69..e297d62 100644
--- a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
@@ -1544,7 +1544,8 @@ static struct omap_hwmod_class_sysconfig omap54xx_usb_host_hs_sysc = {
 	.rev_offs	= 0x0000,
 	.sysc_offs	= 0x0010,
 	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_RESET_STATUS |
-			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET),
+			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET |
+			   SYSC_HAS_RESET_STATUS),
 	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
 			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
 			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
@@ -1598,15 +1599,7 @@ static struct omap_hwmod omap54xx_usb_host_hs_hwmod = {
 	 * hence HWMOD_SWSUP_MSTANDBY
 	 */
 
-	/*
-	 * During system boot; If the hwmod framework resets the module
-	 * the module will have smart idle settings; which can lead to deadlock
-	 * (above Errata Id:i660); so, dont reset the module during boot;
-	 * Use HWMOD_INIT_NO_RESET.
-	 */
-
-	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
-			  HWMOD_INIT_NO_RESET,
+	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
 	.main_clk	= "l3init_60m_fclk",
 	.prcm = {
 		.omap4 = {
-- 
1.8.3.2

[PATCH 2/3] ARM: OMAP2+: hwmod: Fix RESET logic

[Roger Quadros]

In _ocp_softreset(), after _set_softreset() + write_sysconfig(),
the hwmod's sysc_cache will always contain SOFTRESET bit set
so all further writes to sysconfig using this cache will initiate
a repeated SOFTRESET e.g. enable_sysc(). This is true for OMAP3 like
platforms that have RESET_DONE status in the SYSSTATUS register and
so the the SOFTRESET bit in SYSCONFIG is not automatically cleared.
It is not a problem for OMAP4 like platforms that indicate RESET
completion by clearing the SOFTRESET bit in the SYSCONFIG register.

This repeated SOFTRESET is undesired and was the root cause of
USB host issues on OMAP3 platforms when hwmod was allowed to do the
SOFTRESET for the USB Host module.

To fix this we clear the SOFTRESET bit and update the sysconfig
register + sysc_cache using write_sysconfig().

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod.c | 43 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index e3f0eca..615acec 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -399,7 +399,7 @@ static int _set_clockactivity(struct omap_hwmod *oh, u8 clockact, u32 *v)
 }
 
 /**
- * _set_softreset: set OCP_SYSCONFIG.CLOCKACTIVITY bits in @v
+ * _set_softreset: set OCP_SYSCONFIG.SOFTRESET bit in @v
  * @oh: struct omap_hwmod *
  * @v: pointer to register contents to modify
  *
@@ -427,6 +427,36 @@ static int _set_softreset(struct omap_hwmod *oh, u32 *v)
 }
 
 /**
+ * _clr_softreset: clear OCP_SYSCONFIG.SOFTRESET bit in @v
+ * @oh: struct omap_hwmod *
+ * @v: pointer to register contents to modify
+ *
+ * Clear the SOFTRESET bit in @v for hwmod @oh.  Returns -EINVAL upon
+ * error or 0 upon success.
+ */
+static int _clr_softreset(struct omap_hwmod *oh, u32 *v)
+{
+	u32 softrst_mask;
+
+	if (!oh->class->sysc ||
+	    !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET))
+		return -EINVAL;
+
+	if (!oh->class->sysc->sysc_fields) {
+		WARN(1,
+		     "omap_hwmod: %s: sysc_fields absent for sysconfig class\n",
+		     oh->name);
+		return -EINVAL;
+	}
+
+	softrst_mask = (0x1 << oh->class->sysc->sysc_fields->srst_shift);
+
+	*v &= ~softrst_mask;
+
+	return 0;
+}
+
+/**
  * _wait_softreset_complete - wait for an OCP softreset to complete
  * @oh: struct omap_hwmod * to wait on
  *
@@ -1911,6 +1941,12 @@ static int _ocp_softreset(struct omap_hwmod *oh)
 	ret = _set_softreset(oh, &v);
 	if (ret)
 		goto dis_opt_clks;
+
+	_write_sysconfig(v, oh);
+	ret = _clr_softreset(oh, &v);
+	if (ret)
+		goto dis_opt_clks;
+
 	_write_sysconfig(v, oh);
 
 	if (oh->class->sysc->srst_udelay)
@@ -3169,6 +3205,11 @@ int omap_hwmod_softreset(struct omap_hwmod *oh)
 		goto error;
 	_write_sysconfig(v, oh);
 
+	ret = _clr_softreset(oh, &v);
+	if (ret)
+		goto error;
+	_write_sysconfig(v, oh);
+
 error:
 	return ret;
 }
-- 
1.8.3.2

[PATCH 3/3] ARM: OMAP3: hwmod data: Don't prevent RESET of USB Host module

[Roger Quadros]

Unlike what the comment states, errata i660 does not state that we
can't RESET the USB host module. Instead it states that RESET is the
only way to recover from a deadlock situation.

RESET ensures that the module is in a known good state irrespective
of what bootloader does with the module, so it must be done at boot.

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
index 9e56fab..d337429 100644
--- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
@@ -1943,7 +1943,8 @@ static struct omap_hwmod_class_sysconfig omap3xxx_usb_host_hs_sysc = {
 	.syss_offs	= 0x0014,
 	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_CLOCKACTIVITY |
 			   SYSC_HAS_SIDLEMODE | SYSC_HAS_ENAWAKEUP |
-			   SYSC_HAS_SOFTRESET | SYSC_HAS_AUTOIDLE),
+			   SYSC_HAS_SOFTRESET | SYSC_HAS_AUTOIDLE |
+			   SYSS_HAS_RESET_STATUS),
 	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
 			   MSTANDBY_FORCE | MSTANDBY_NO | MSTANDBY_SMART),
 	.sysc_fields	= &omap_hwmod_sysc_type1,
@@ -2021,15 +2022,7 @@ static struct omap_hwmod omap3xxx_usb_host_hs_hwmod = {
 	 * hence HWMOD_SWSUP_MSTANDBY
 	 */
 
-	/*
-	 * During system boot; If the hwmod framework resets the module
-	 * the module will have smart idle settings; which can lead to deadlock
-	 * (above Errata Id:i660); so, dont reset the module during boot;
-	 * Use HWMOD_INIT_NO_RESET.
-	 */
-
-	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
-			  HWMOD_INIT_NO_RESET,
+	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
 };
 
 /*
-- 
1.8.3.2

Re: [PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[Tomi Valkeinen]

[-- Attachment #1.1: Type: text/plain, Size: 900 bytes --]

On 2013-12-03 16:25, Roger Quadros wrote:
> Hi,
> 
> This is a follow up solution to the original series in [1]
> 
> The first patch fixes the OMAP4 Panda USB detection problems on 3.13-rc1
> with u-boot v2013.10.
> 
> The remaining 2 patches are required if SOFTRESET needs to be done for the
> USB Host module on OMAP3 platforms.
> 
> Patch 2 fixes the hwmod RESET logic to prevent multiple SOFTRESETs
> being issued to the modules. This multiple SOFTRESET was causing problems
> with OMAP3 USB Host module. On Beagleboard C4 this is seen as failure to
> mount NFS root over external USB to Ethernet device.
> 
> This might be the reason why HWMOD_INIT_NO_RESET was used for the OMAP
> USB host module in OMAP3 hwmod data and just carried forward in OMAP4
> and OMAP5 hwmod data as well.
> 
> cheers,
> -roger

Tested on Panda and Beagle xM. Works fine for me.

 Tomi



[-- Attachment #1.2: OpenPGP digital signature --]
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[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

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Re: [PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[Tony Lindgren]

* Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 02:01]:
> On 2013-12-03 16:25, Roger Quadros wrote:
> > Hi,
> > 
> > This is a follow up solution to the original series in [1]
> > 
> > The first patch fixes the OMAP4 Panda USB detection problems on 3.13-rc1
> > with u-boot v2013.10.
> > 
> > The remaining 2 patches are required if SOFTRESET needs to be done for the
> > USB Host module on OMAP3 platforms.
> > 
> > Patch 2 fixes the hwmod RESET logic to prevent multiple SOFTRESETs
> > being issued to the modules. This multiple SOFTRESET was causing problems
> > with OMAP3 USB Host module. On Beagleboard C4 this is seen as failure to
> > mount NFS root over external USB to Ethernet device.
> > 
> > This might be the reason why HWMOD_INIT_NO_RESET was used for the OMAP
> > USB host module in OMAP3 hwmod data and just carried forward in OMAP4
> > and OMAP5 hwmod data as well.
> > 
> > cheers,
> > -roger
> 
> Tested on Panda and Beagle xM. Works fine for me.

Looks like we should merge these as regression fixes during the -rc
cycle. Paul should take a look at these first though.

Regards,

Tony

Re: [PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[Roger Quadros]

Tony,

On 12/05/2013 08:48 PM, Tony Lindgren wrote:
> * Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 02:01]:
>> On 2013-12-03 16:25, Roger Quadros wrote:
>>> Hi,
>>>
>>> This is a follow up solution to the original series in [1]
>>>
>>> The first patch fixes the OMAP4 Panda USB detection problems on 3.13-rc1
>>> with u-boot v2013.10.
>>>
>>> The remaining 2 patches are required if SOFTRESET needs to be done for the
>>> USB Host module on OMAP3 platforms.
>>>
>>> Patch 2 fixes the hwmod RESET logic to prevent multiple SOFTRESETs
>>> being issued to the modules. This multiple SOFTRESET was causing problems
>>> with OMAP3 USB Host module. On Beagleboard C4 this is seen as failure to
>>> mount NFS root over external USB to Ethernet device.
>>>
>>> This might be the reason why HWMOD_INIT_NO_RESET was used for the OMAP
>>> USB host module in OMAP3 hwmod data and just carried forward in OMAP4
>>> and OMAP5 hwmod data as well.
>>>
>>> cheers,
>>> -roger
>>
>> Tested on Panda and Beagle xM. Works fine for me.
> 
> Looks like we should merge these as regression fixes during the -rc
> cycle. Paul should take a look at these first though.

At least the first one must be taken ASAP. The other two would be nice to have though.

cheers,
-roger

Re: [PATCH 1/3] ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module

[Paul Walmsley]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 3741 bytes --]

Hi Benoît,

On Tue, 3 Dec 2013, Roger Quadros wrote:

> Without this, the USB devices are sometimes not detected on OMAP4 Panda
> with u-boot v2013.10.
> 
> Unlike what the comment states, errata i660 does not state that we
> can't RESET the USB host module. Instead it states that RESET is the
> only way to recover from a deadlock situation.
> 
> RESET ensures that the module is in a known good state irrespective
> of what bootloader does with the module, so it must be done at boot.
> 
> Reported-by: Tomi Valkeinen <tomi.valkeinen-l0cyMroinI0@public.gmane.org>
> Signed-off-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>

Acked-by: Paul Walmsley <paul-DWxLp4Yu+b8AvxtiuMwx3w@public.gmane.org>

Will you pick this up for the -rc series, or do you want me or Tony to?  
Roger writes that this one's pretty important.


- Paul


> ---
>  arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 12 ++----------
>  arch/arm/mach-omap2/omap_hwmod_54xx_data.c | 13 +++----------
>  2 files changed, 5 insertions(+), 20 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> index 1e5b12c..3318cae9 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> @@ -2937,7 +2937,7 @@ static struct omap_hwmod_class_sysconfig omap44xx_usb_host_hs_sysc = {
>  	.sysc_offs	= 0x0010,
>  	.syss_offs	= 0x0014,
>  	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_SIDLEMODE |
> -			   SYSC_HAS_SOFTRESET),
> +			   SYSC_HAS_SOFTRESET | SYSC_HAS_RESET_STATUS),
>  	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
>  			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
>  			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
> @@ -3001,15 +3001,7 @@ static struct omap_hwmod omap44xx_usb_host_hs_hwmod = {
>  	 * hence HWMOD_SWSUP_MSTANDBY
>  	 */
>  
> -	/*
> -	 * During system boot; If the hwmod framework resets the module
> -	 * the module will have smart idle settings; which can lead to deadlock
> -	 * (above Errata Id:i660); so, dont reset the module during boot;
> -	 * Use HWMOD_INIT_NO_RESET.
> -	 */
> -
> -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
> -			  HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
>  };
>  
>  /*
> diff --git a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> index 9e08d69..e297d62 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> @@ -1544,7 +1544,8 @@ static struct omap_hwmod_class_sysconfig omap54xx_usb_host_hs_sysc = {
>  	.rev_offs	= 0x0000,
>  	.sysc_offs	= 0x0010,
>  	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_RESET_STATUS |
> -			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET),
> +			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET |
> +			   SYSC_HAS_RESET_STATUS),
>  	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
>  			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
>  			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
> @@ -1598,15 +1599,7 @@ static struct omap_hwmod omap54xx_usb_host_hs_hwmod = {
>  	 * hence HWMOD_SWSUP_MSTANDBY
>  	 */
>  
> -	/*
> -	 * During system boot; If the hwmod framework resets the module
> -	 * the module will have smart idle settings; which can lead to deadlock
> -	 * (above Errata Id:i660); so, dont reset the module during boot;
> -	 * Use HWMOD_INIT_NO_RESET.
> -	 */
> -
> -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
> -			  HWMOD_INIT_NO_RESET,
> +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
>  	.main_clk	= "l3init_60m_fclk",
>  	.prcm = {
>  		.omap4 = {
> -- 
> 1.8.3.2
> 


- Paul

Re: [PATCH 2/3] ARM: OMAP2+: hwmod: Fix RESET logic

[Paul Walmsley]

Hi Roger,

On Tue, 3 Dec 2013, Roger Quadros wrote:

> In _ocp_softreset(), after _set_softreset() + write_sysconfig(),
> the hwmod's sysc_cache will always contain SOFTRESET bit set
> so all further writes to sysconfig using this cache will initiate
> a repeated SOFTRESET e.g. enable_sysc(). This is true for OMAP3 like
> platforms that have RESET_DONE status in the SYSSTATUS register and
> so the the SOFTRESET bit in SYSCONFIG is not automatically cleared.
> It is not a problem for OMAP4 like platforms that indicate RESET
> completion by clearing the SOFTRESET bit in the SYSCONFIG register.
> 
> This repeated SOFTRESET is undesired and was the root cause of
> USB host issues on OMAP3 platforms when hwmod was allowed to do the
> SOFTRESET for the USB Host module.

Doh :-(

Nice catch.  Renamed _clr_softreset() to _clear_softreset() and queued 
the following for v3.13-rc.


- Paul


From: Roger Quadros <rogerq@ti.com>

ARM: OMAP2+: hwmod: Fix SOFTRESET logic

In _ocp_softreset(), after _set_softreset() + write_sysconfig(),
the hwmod's sysc_cache will always contain SOFTRESET bit set
so all further writes to sysconfig using this cache will initiate
a repeated SOFTRESET e.g. enable_sysc(). This is true for OMAP3 like
platforms that have RESET_DONE status in the SYSSTATUS register and
so the the SOFTRESET bit in SYSCONFIG is not automatically cleared.
It is not a problem for OMAP4 like platforms that indicate RESET
completion by clearing the SOFTRESET bit in the SYSCONFIG register.

This repeated SOFTRESET is undesired and was the root cause of
USB host issues on OMAP3 platforms when hwmod was allowed to do the
SOFTRESET for the USB Host module.

To fix this we clear the SOFTRESET bit and update the sysconfig
register + sysc_cache using write_sysconfig().

Signed-off-by: Roger Quadros <rogerq@ti.com>
[paul@pwsan.com: renamed _clr_softreset() to _clear_softreset()]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
---
 arch/arm/mach-omap2/omap_hwmod.c | 43 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index e3f0ecaf87dd..cacc0c7e8634 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -399,7 +399,7 @@ static int _set_clockactivity(struct omap_hwmod *oh, u8 clockact, u32 *v)
 }
 
 /**
- * _set_softreset: set OCP_SYSCONFIG.CLOCKACTIVITY bits in @v
+ * _set_softreset: set OCP_SYSCONFIG.SOFTRESET bit in @v
  * @oh: struct omap_hwmod *
  * @v: pointer to register contents to modify
  *
@@ -427,6 +427,36 @@ static int _set_softreset(struct omap_hwmod *oh, u32 *v)
 }
 
 /**
+ * _clear_softreset: clear OCP_SYSCONFIG.SOFTRESET bit in @v
+ * @oh: struct omap_hwmod *
+ * @v: pointer to register contents to modify
+ *
+ * Clear the SOFTRESET bit in @v for hwmod @oh.  Returns -EINVAL upon
+ * error or 0 upon success.
+ */
+static int _clear_softreset(struct omap_hwmod *oh, u32 *v)
+{
+	u32 softrst_mask;
+
+	if (!oh->class->sysc ||
+	    !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET))
+		return -EINVAL;
+
+	if (!oh->class->sysc->sysc_fields) {
+		WARN(1,
+		     "omap_hwmod: %s: sysc_fields absent for sysconfig class\n",
+		     oh->name);
+		return -EINVAL;
+	}
+
+	softrst_mask = (0x1 << oh->class->sysc->sysc_fields->srst_shift);
+
+	*v &= ~softrst_mask;
+
+	return 0;
+}
+
+/**
  * _wait_softreset_complete - wait for an OCP softreset to complete
  * @oh: struct omap_hwmod * to wait on
  *
@@ -1911,6 +1941,12 @@ static int _ocp_softreset(struct omap_hwmod *oh)
 	ret = _set_softreset(oh, &v);
 	if (ret)
 		goto dis_opt_clks;
+
+	_write_sysconfig(v, oh);
+	ret = _clear_softreset(oh, &v);
+	if (ret)
+		goto dis_opt_clks;
+
 	_write_sysconfig(v, oh);
 
 	if (oh->class->sysc->srst_udelay)
@@ -3169,6 +3205,11 @@ int omap_hwmod_softreset(struct omap_hwmod *oh)
 		goto error;
 	_write_sysconfig(v, oh);
 
+	ret = _clear_softreset(oh, &v);
+	if (ret)
+		goto error;
+	_write_sysconfig(v, oh);
+
 error:
 	return ret;
 }
-- 
1.8.4.4

Re: [PATCH 3/3] ARM: OMAP3: hwmod data: Don't prevent RESET of USB Host module

[Paul Walmsley]

On Tue, 3 Dec 2013, Roger Quadros wrote:

> Unlike what the comment states, errata i660 does not state that we
> can't RESET the USB host module. Instead it states that RESET is the
> only way to recover from a deadlock situation.
> 
> RESET ensures that the module is in a known good state irrespective
> of what bootloader does with the module, so it must be done at boot.
> 
> Signed-off-by: Roger Quadros <rogerq@ti.com>

Thanks, queued for v3.13-rc.

- Paul

Re: [PATCH v2 0/3] ARM: OMAP2+: USB Host bug fixes for 3.13 rc

[Paul Walmsley]

On Wed, 4 Dec 2013, Tomi Valkeinen wrote:

> Tested on Panda and Beagle xM. Works fine for me.

Thanks, added your Tested-by's to both patches that I've queued.


- Paul
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Re: [PATCH 1/3] ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module

[Tony Lindgren]

* Paul Walmsley <paul@pwsan.com> [131208 17:27]:
> Hi Benoît,
> 
> On Tue, 3 Dec 2013, Roger Quadros wrote:
> 
> > Without this, the USB devices are sometimes not detected on OMAP4 Panda
> > with u-boot v2013.10.
> > 
> > Unlike what the comment states, errata i660 does not state that we
> > can't RESET the USB host module. Instead it states that RESET is the
> > only way to recover from a deadlock situation.
> > 
> > RESET ensures that the module is in a known good state irrespective
> > of what bootloader does with the module, so it must be done at boot.
> > 
> > Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > Signed-off-by: Roger Quadros <rogerq@ti.com>
> 
> Acked-by: Paul Walmsley <paul@pwsan.com>
> 
> Will you pick this up for the -rc series, or do you want me or Tony to?  
> Roger writes that this one's pretty important.

I suggest that you just queue this with your other fixes so we get
things working.

Regards,

Tony
 
 
> >  arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 12 ++----------
> >  arch/arm/mach-omap2/omap_hwmod_54xx_data.c | 13 +++----------
> >  2 files changed, 5 insertions(+), 20 deletions(-)
> > 
> > diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> > index 1e5b12c..3318cae9 100644
> > --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> > +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
> > @@ -2937,7 +2937,7 @@ static struct omap_hwmod_class_sysconfig omap44xx_usb_host_hs_sysc = {
> >  	.sysc_offs	= 0x0010,
> >  	.syss_offs	= 0x0014,
> >  	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_SIDLEMODE |
> > -			   SYSC_HAS_SOFTRESET),
> > +			   SYSC_HAS_SOFTRESET | SYSC_HAS_RESET_STATUS),
> >  	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
> >  			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
> >  			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
> > @@ -3001,15 +3001,7 @@ static struct omap_hwmod omap44xx_usb_host_hs_hwmod = {
> >  	 * hence HWMOD_SWSUP_MSTANDBY
> >  	 */
> >  
> > -	/*
> > -	 * During system boot; If the hwmod framework resets the module
> > -	 * the module will have smart idle settings; which can lead to deadlock
> > -	 * (above Errata Id:i660); so, dont reset the module during boot;
> > -	 * Use HWMOD_INIT_NO_RESET.
> > -	 */
> > -
> > -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
> > -			  HWMOD_INIT_NO_RESET,
> > +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
> >  };
> >  
> >  /*
> > diff --git a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> > index 9e08d69..e297d62 100644
> > --- a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> > +++ b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
> > @@ -1544,7 +1544,8 @@ static struct omap_hwmod_class_sysconfig omap54xx_usb_host_hs_sysc = {
> >  	.rev_offs	= 0x0000,
> >  	.sysc_offs	= 0x0010,
> >  	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_RESET_STATUS |
> > -			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET),
> > +			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET |
> > +			   SYSC_HAS_RESET_STATUS),
> >  	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
> >  			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
> >  			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
> > @@ -1598,15 +1599,7 @@ static struct omap_hwmod omap54xx_usb_host_hs_hwmod = {
> >  	 * hence HWMOD_SWSUP_MSTANDBY
> >  	 */
> >  
> > -	/*
> > -	 * During system boot; If the hwmod framework resets the module
> > -	 * the module will have smart idle settings; which can lead to deadlock
> > -	 * (above Errata Id:i660); so, dont reset the module during boot;
> > -	 * Use HWMOD_INIT_NO_RESET.
> > -	 */
> > -
> > -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
> > -			  HWMOD_INIT_NO_RESET,
> > +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
> >  	.main_clk	= "l3init_60m_fclk",
> >  	.prcm = {
> >  		.omap4 = {
> > -- 
> > 1.8.3.2
> > 
> 
> 
> - Paul

Re: [PATCH 1/3] ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module

[Paul Walmsley]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1172 bytes --]

On Sun, 8 Dec 2013, Tony Lindgren wrote:

> * Paul Walmsley <paul@pwsan.com> [131208 17:27]:
> > On Tue, 3 Dec 2013, Roger Quadros wrote:
> > 
> > > Without this, the USB devices are sometimes not detected on OMAP4 Panda
> > > with u-boot v2013.10.
> > > 
> > > Unlike what the comment states, errata i660 does not state that we
> > > can't RESET the USB host module. Instead it states that RESET is the
> > > only way to recover from a deadlock situation.
> > > 
> > > RESET ensures that the module is in a known good state irrespective
> > > of what bootloader does with the module, so it must be done at boot.
> > > 
> > > Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> > > Signed-off-by: Roger Quadros <rogerq@ti.com>
> > 
> > Acked-by: Paul Walmsley <paul@pwsan.com>
> > 
> > Will you pick this up for the -rc series, or do you want me or Tony to?  
> > Roger writes that this one's pretty important.
> 
> I suggest that you just queue this with your other fixes so we get
> things working.

I'm going to wait until tomorrow anyway to see if Sathya responds to my 
other E-mail, so maybe Benoît will let us know by then.


- Paul

Re: [PATCH 1/3] ARM: OMAP4+: hwmod data: Don't prevent RESET of USB Host module

[Benoit Cousson]

Salut Paul,

On 08/12/2013 17:26, Paul Walmsley wrote:
> Hi Benoît,
>
> On Tue, 3 Dec 2013, Roger Quadros wrote:
>
>> Without this, the USB devices are sometimes not detected on OMAP4 Panda
>> with u-boot v2013.10.
>>
>> Unlike what the comment states, errata i660 does not state that we
>> can't RESET the USB host module. Instead it states that RESET is the
>> only way to recover from a deadlock situation.
>>
>> RESET ensures that the module is in a known good state irrespective
>> of what bootloader does with the module, so it must be done at boot.
>>
>> Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>
> Acked-by: Paul Walmsley <paul@pwsan.com>
>
> Will you pick this up for the -rc series, or do you want me or Tony to?
> Roger writes that this one's pretty important.

I guess, it is better for you to take it. I don't have anything queued 
for -rc.

Acked-by: Benoit Cousson <bcousson@baylibre.com>

Thanks,
Benoit

>
>
> - Paul
>
>
>> ---
>>   arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 12 ++----------
>>   arch/arm/mach-omap2/omap_hwmod_54xx_data.c | 13 +++----------
>>   2 files changed, 5 insertions(+), 20 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> index 1e5b12c..3318cae9 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
>> @@ -2937,7 +2937,7 @@ static struct omap_hwmod_class_sysconfig omap44xx_usb_host_hs_sysc = {
>>   	.sysc_offs	= 0x0010,
>>   	.syss_offs	= 0x0014,
>>   	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_SIDLEMODE |
>> -			   SYSC_HAS_SOFTRESET),
>> +			   SYSC_HAS_SOFTRESET | SYSC_HAS_RESET_STATUS),
>>   	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
>>   			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
>>   			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
>> @@ -3001,15 +3001,7 @@ static struct omap_hwmod omap44xx_usb_host_hs_hwmod = {
>>   	 * hence HWMOD_SWSUP_MSTANDBY
>>   	 */
>>
>> -	/*
>> -	 * During system boot; If the hwmod framework resets the module
>> -	 * the module will have smart idle settings; which can lead to deadlock
>> -	 * (above Errata Id:i660); so, dont reset the module during boot;
>> -	 * Use HWMOD_INIT_NO_RESET.
>> -	 */
>> -
>> -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
>> -			  HWMOD_INIT_NO_RESET,
>> +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
>>   };
>>
>>   /*
>> diff --git a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
>> index 9e08d69..e297d62 100644
>> --- a/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
>> +++ b/arch/arm/mach-omap2/omap_hwmod_54xx_data.c
>> @@ -1544,7 +1544,8 @@ static struct omap_hwmod_class_sysconfig omap54xx_usb_host_hs_sysc = {
>>   	.rev_offs	= 0x0000,
>>   	.sysc_offs	= 0x0010,
>>   	.sysc_flags	= (SYSC_HAS_MIDLEMODE | SYSC_HAS_RESET_STATUS |
>> -			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET),
>> +			   SYSC_HAS_SIDLEMODE | SYSC_HAS_SOFTRESET |
>> +			   SYSC_HAS_RESET_STATUS),
>>   	.idlemodes	= (SIDLE_FORCE | SIDLE_NO | SIDLE_SMART |
>>   			   SIDLE_SMART_WKUP | MSTANDBY_FORCE | MSTANDBY_NO |
>>   			   MSTANDBY_SMART | MSTANDBY_SMART_WKUP),
>> @@ -1598,15 +1599,7 @@ static struct omap_hwmod omap54xx_usb_host_hs_hwmod = {
>>   	 * hence HWMOD_SWSUP_MSTANDBY
>>   	 */
>>
>> -	/*
>> -	 * During system boot; If the hwmod framework resets the module
>> -	 * the module will have smart idle settings; which can lead to deadlock
>> -	 * (above Errata Id:i660); so, dont reset the module during boot;
>> -	 * Use HWMOD_INIT_NO_RESET.
>> -	 */
>> -
>> -	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY |
>> -			  HWMOD_INIT_NO_RESET,
>> +	.flags		= HWMOD_SWSUP_SIDLE | HWMOD_SWSUP_MSTANDBY,
>>   	.main_clk	= "l3init_60m_fclk",
>>   	.prcm = {
>>   		.omap4 = {
>> --
>> 1.8.3.2
>>
>
>
> - Paul
>


-- 
Benoît Cousson
BayLibre
Embedded Linux Technology Lab
www.baylibre.com