diff mbox

ARM: pxa: prevent PXA270 occasional reboot freezes

Message ID 1386650355-2503-1-git-send-email-ynvich@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sergey Yanovich Dec. 10, 2013, 4:39 a.m. UTC
Erratum 71 of PXA270M Processor Family Specification Update
(April 19, 2010) explains that watchdog reset time is just
8us insead of 10ms in EMTS.

If SDRAM is not reset, it causes memory bus congestion and
the device hangs. We put SDRAM in selfresh mode before watchdog
reset, removing potential freezes.

Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40
reboots. With this patch it has successfully rebooted 500 times.

Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
---
 arch/arm/mach-pxa/reset.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Haojian Zhuang Dec. 10, 2013, 8:43 a.m. UTC | #1
On 12/10/2013 12:39 PM, Sergei Ianovich wrote:
> Erratum 71 of PXA270M Processor Family Specification Update
> (April 19, 2010) explains that watchdog reset time is just
> 8us insead of 10ms in EMTS.
>
> If SDRAM is not reset, it causes memory bus congestion and
> the device hangs. We put SDRAM in selfresh mode before watchdog
> reset, removing potential freezes.
>
> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40
> reboots. With this patch it has successfully rebooted 500 times.
>
> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
> ---
>   arch/arm/mach-pxa/reset.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
> index 0d5dd64..263b152 100644
> --- a/arch/arm/mach-pxa/reset.c
> +++ b/arch/arm/mach-pxa/reset.c
> @@ -13,6 +13,7 @@
>
>   #include <mach/regs-ost.h>
>   #include <mach/reset.h>
> +#include <mach/smemc.h>
>
>   unsigned int reset_status;
>   EXPORT_SYMBOL(reset_status);
> @@ -81,6 +82,12 @@ static void do_hw_reset(void)
>   	writel_relaxed(OSSR_M3, OSSR);
>   	/* ... in 100 ms */
>   	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
> +	/*
> +	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
> +	 * we put SDRAM into self-refresh to prevent that
> +	 */
> +	while (1)
> +		writel_relaxed(MDREFR_SLFRSH, MDREFR);
>   }
>
>   void pxa_restart(enum reboot_mode mode, const char *cmd)
> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char *cmd)
>   		break;
>   	}
>   }
> -
>

Hi Daniel/Marek/Igor,

Could you help to try this patch? I'm lack of PXA27x board.

Best Regards
Haojian
Daniel Mack Dec. 10, 2013, 10:48 a.m. UTC | #2
On 12/10/2013 09:43 AM, Haojian Zhuang wrote:
> On 12/10/2013 12:39 PM, Sergei Ianovich wrote:
>> Erratum 71 of PXA270M Processor Family Specification Update
>> (April 19, 2010) explains that watchdog reset time is just
>> 8us insead of 10ms in EMTS.
>>
>> If SDRAM is not reset, it causes memory bus congestion and
>> the device hangs. We put SDRAM in selfresh mode before watchdog
>> reset, removing potential freezes.
>>
>> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40
>> reboots. With this patch it has successfully rebooted 500 times.
>>
>> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
>> ---
>>   arch/arm/mach-pxa/reset.c | 8 +++++++-
>>   1 file changed, 7 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
>> index 0d5dd64..263b152 100644
>> --- a/arch/arm/mach-pxa/reset.c
>> +++ b/arch/arm/mach-pxa/reset.c
>> @@ -13,6 +13,7 @@
>>
>>   #include <mach/regs-ost.h>
>>   #include <mach/reset.h>
>> +#include <mach/smemc.h>
>>
>>   unsigned int reset_status;
>>   EXPORT_SYMBOL(reset_status);
>> @@ -81,6 +82,12 @@ static void do_hw_reset(void)
>>   	writel_relaxed(OSSR_M3, OSSR);
>>   	/* ... in 100 ms */
>>   	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
>> +	/*
>> +	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
>> +	 * we put SDRAM into self-refresh to prevent that
>> +	 */
>> +	while (1)
>> +		writel_relaxed(MDREFR_SLFRSH, MDREFR);
>>   }
>>
>>   void pxa_restart(enum reboot_mode mode, const char *cmd)
>> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char *cmd)
>>   		break;
>>   	}
>>   }
>> -
>>
> 
> Hi Daniel/Marek/Igor,
> 
> Could you help to try this patch? I'm lack of PXA27x board.

I don't have any either right now ...


Daniel
Marek Vasut Dec. 10, 2013, 6:31 p.m. UTC | #3
On Tuesday, December 10, 2013 at 11:48:59 AM, Daniel Mack wrote:
> On 12/10/2013 09:43 AM, Haojian Zhuang wrote:
> > On 12/10/2013 12:39 PM, Sergei Ianovich wrote:
> >> Erratum 71 of PXA270M Processor Family Specification Update
> >> (April 19, 2010) explains that watchdog reset time is just
> >> 8us insead of 10ms in EMTS.
> >> 
> >> If SDRAM is not reset, it causes memory bus congestion and
> >> the device hangs. We put SDRAM in selfresh mode before watchdog
> >> reset, removing potential freezes.
> >> 
> >> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40
> >> reboots. With this patch it has successfully rebooted 500 times.
> >> 
> >> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
> >> ---
> >> 
> >>   arch/arm/mach-pxa/reset.c | 8 +++++++-
> >>   1 file changed, 7 insertions(+), 1 deletion(-)
> >> 
> >> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
> >> index 0d5dd64..263b152 100644
> >> --- a/arch/arm/mach-pxa/reset.c
> >> +++ b/arch/arm/mach-pxa/reset.c
> >> @@ -13,6 +13,7 @@
> >> 
> >>   #include <mach/regs-ost.h>
> >>   #include <mach/reset.h>
> >> 
> >> +#include <mach/smemc.h>
> >> 
> >>   unsigned int reset_status;
> >>   EXPORT_SYMBOL(reset_status);
> >> 
> >> @@ -81,6 +82,12 @@ static void do_hw_reset(void)
> >> 
> >>   	writel_relaxed(OSSR_M3, OSSR);
> >>   	/* ... in 100 ms */
> >>   	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
> >> 
> >> +	/*
> >> +	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
> >> +	 * we put SDRAM into self-refresh to prevent that
> >> +	 */
> >> +	while (1)
> >> +		writel_relaxed(MDREFR_SLFRSH, MDREFR);
> >> 
> >>   }
> >>   
> >>   void pxa_restart(enum reboot_mode mode, const char *cmd)
> >> 
> >> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char
> >> *cmd)
> >> 
> >>   		break;
> >>   	
> >>   	}
> >>   
> >>   }
> >> 
> >> -
> > 
> > Hi Daniel/Marek/Igor,
> > 
> > Could you help to try this patch? I'm lack of PXA27x board.
> 
> I don't have any either right now ...

On VPAC270

Tested-by: Marek Vasut <marex@denx.de>

Best regards,
Marek Vasut
Haojian Zhuang Dec. 11, 2013, 7:18 a.m. UTC | #4
On 12/11/2013 02:31 AM, Marek Vasut wrote:
> On Tuesday, December 10, 2013 at 11:48:59 AM, Daniel Mack wrote:
>> On 12/10/2013 09:43 AM, Haojian Zhuang wrote:
>>> On 12/10/2013 12:39 PM, Sergei Ianovich wrote:
>>>> Erratum 71 of PXA270M Processor Family Specification Update
>>>> (April 19, 2010) explains that watchdog reset time is just
>>>> 8us insead of 10ms in EMTS.
>>>>
>>>> If SDRAM is not reset, it causes memory bus congestion and
>>>> the device hangs. We put SDRAM in selfresh mode before watchdog
>>>> reset, removing potential freezes.
>>>>
>>>> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40
>>>> reboots. With this patch it has successfully rebooted 500 times.
>>>>
>>>> Signed-off-by: Sergei Ianovich <ynvich@gmail.com>
>>>> ---
>>>>
>>>>    arch/arm/mach-pxa/reset.c | 8 +++++++-
>>>>    1 file changed, 7 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
>>>> index 0d5dd64..263b152 100644
>>>> --- a/arch/arm/mach-pxa/reset.c
>>>> +++ b/arch/arm/mach-pxa/reset.c
>>>> @@ -13,6 +13,7 @@
>>>>
>>>>    #include <mach/regs-ost.h>
>>>>    #include <mach/reset.h>
>>>>
>>>> +#include <mach/smemc.h>
>>>>
>>>>    unsigned int reset_status;
>>>>    EXPORT_SYMBOL(reset_status);
>>>>
>>>> @@ -81,6 +82,12 @@ static void do_hw_reset(void)
>>>>
>>>>    	writel_relaxed(OSSR_M3, OSSR);
>>>>    	/* ... in 100 ms */
>>>>    	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
>>>>
>>>> +	/*
>>>> +	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
>>>> +	 * we put SDRAM into self-refresh to prevent that
>>>> +	 */
>>>> +	while (1)
>>>> +		writel_relaxed(MDREFR_SLFRSH, MDREFR);
>>>>
>>>>    }
>>>>
>>>>    void pxa_restart(enum reboot_mode mode, const char *cmd)
>>>>
>>>> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char
>>>> *cmd)
>>>>
>>>>    		break;
>>>>    	
>>>>    	}
>>>>
>>>>    }
>>>>
>>>> -
>>>
>>> Hi Daniel/Marek/Igor,
>>>
>>> Could you help to try this patch? I'm lack of PXA27x board.
>>
>> I don't have any either right now ...
>
> On VPAC270
>
> Tested-by: Marek Vasut <marex@denx.de>
>
> Best regards,
> Marek Vasut
>

Applied.

Thanks
Haojian
diff mbox

Patch

diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c
index 0d5dd64..263b152 100644
--- a/arch/arm/mach-pxa/reset.c
+++ b/arch/arm/mach-pxa/reset.c
@@ -13,6 +13,7 @@ 
 
 #include <mach/regs-ost.h>
 #include <mach/reset.h>
+#include <mach/smemc.h>
 
 unsigned int reset_status;
 EXPORT_SYMBOL(reset_status);
@@ -81,6 +82,12 @@  static void do_hw_reset(void)
 	writel_relaxed(OSSR_M3, OSSR);
 	/* ... in 100 ms */
 	writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3);
+	/*
+	 * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71)
+	 * we put SDRAM into self-refresh to prevent that
+	 */
+	while (1)
+		writel_relaxed(MDREFR_SLFRSH, MDREFR);
 }
 
 void pxa_restart(enum reboot_mode mode, const char *cmd)
@@ -104,4 +111,3 @@  void pxa_restart(enum reboot_mode mode, const char *cmd)
 		break;
 	}
 }
-