[PATCH] Temporary fix for ethernet rx intr hang issue and Disable cache

[ragu nath]

Hi Sebastian,

If we want to use cache flush/invalidate calls, what is the general
method one has to follow?
I saw the if_cgem driver, but it is somewhat different from cpsw
driver. What are all the places which may need these calls?

Thanks,
Ragunath

On Fri, Jul 10, 2015 at 4:29 AM, ragu nath <ragunath3252 at gmail.com> wrote:
> Hi Sebastian,
>
> I read about rtems_cache_coherent_allocate(). I understand first we
> need to add an area to use this.
> I added rtems_cache_coherent_add_area(bsp_nocache_heap_begin,(uintptr_t)
> bsp_nocache_heap_size); in bsp start.
> Is that right? I do not know how bsp_nocache_heap_begin &
> bsp_nocache_heap_size are defined. How to define/check correct vaules
> for them?
>
> Can you pls explain how to use rtems_cache_coherent_allocate? I am not
> sure which memory needs to be allocated with this.
> Do we need to make the mbufs part of this memory?
>
>
> Thanks,
> Ragunath
>
>
> On Mon, Jun 29, 2015 at 12:49 PM, Sebastian Huber
> <sebastian.huber at embedded-brains.de> wrote:
>>
>>
>> On 25/06/15 18:20, ragunath wrote:
>>>
>>> This patch has two changes that are needed for networking to work in BBB.
>>> We disable cache as it is causing random values to be learned in the cpsw
>>> Address
>>> Lookup Engine(ALE) causing tx to fail. Vector enable is done after handler
>>> is called by the server task.
>>>
>>> ---
>>>   c/src/lib/libbsp/arm/beagle/irq.c                 | 2 ++
>>>   c/src/lib/libbsp/arm/beagle/startup/bspstartmmu.c | 8 +++++---
>>>   2 files changed, 7 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/c/src/lib/libbsp/arm/beagle/irq.c
>>> b/c/src/lib/libbsp/arm/beagle/irq.c
>>> index c6485cd..64e7756 100644
>>> --- a/c/src/lib/libbsp/arm/beagle/irq.c
>>> +++ b/c/src/lib/libbsp/arm/beagle/irq.c
>>> @@ -73,6 +73,7 @@ void bsp_interrupt_dispatch(void)
>>>         _ARMV4_Status_restore(psr);
>>>   +    if(!(irq == 40 || irq == 41 || irq == 42 || irq == 43))
>>>       bsp_interrupt_vector_enable(irq);
>>>     }
>>>   }
>>
>>
>> Why not remove the bsp_interrupt_vector_disable/enable() calls in
>> bsp_interrupt_dispatch() unconditionally?
>>
>>
>>> @@ -94,6 +95,7 @@ rtems_status_code
>>> bsp_interrupt_vector_enable(rtems_vector_number vector)
>>>     uint32_t mask, cur;
>>>     uint32_t mir_reg = get_mir_reg(vector, &mask);
>>>   +  irqs_enabled[vector] = 1;
>>>     cur = mmio_read(omap_intr.base + mir_reg);
>>>     mmio_write(omap_intr.base + mir_reg, cur & ~mask);
>>>     flush_data_cache();
>>> diff --git a/c/src/lib/libbsp/arm/beagle/startup/bspstartmmu.c
>>> b/c/src/lib/libbsp/arm/beagle/startup/bspstartmmu.c
>>> index 157edfa..6cd0f38 100644
>>> --- a/c/src/lib/libbsp/arm/beagle/startup/bspstartmmu.c
>>> +++ b/c/src/lib/libbsp/arm/beagle/startup/bspstartmmu.c
>>> @@ -44,15 +44,17 @@ BSP_START_TEXT_SECTION void
>>> beagle_setup_mmu_and_cache(void)
>>>   {
>>>     /* turn mmu off first in case it's on */
>>>     uint32_t ctrl = arm_cp15_start_setup_mmu_and_cache(
>>> -    ARM_CP15_CTRL_M | ARM_CP15_CTRL_A, /* clear - mmu off */
>>> +    ARM_CP15_CTRL_M | ARM_CP15_CTRL_A | ARM_CP15_CTRL_I |
>>> ARM_CP15_CTRL_C,     /* clear - mmu off */
>>>       ARM_CP15_CTRL_AFE | ARM_CP15_CTRL_Z
>>>     );
>>>   -  arm_cp15_start_setup_translation_table_and_enable_mmu_and_cache(
>>> -    ctrl,
>>> +  arm_cp15_start_setup_translation_table(
>>>       (uint32_t *) bsp_translation_table_base,
>>>       ARM_MMU_DEFAULT_CLIENT_DOMAIN,
>>>       &beagle_mmu_config_table[0],
>>>       RTEMS_ARRAY_SIZE(beagle_mmu_config_table)
>>>     );
>>> +
>>> +  ctrl |= ARM_CP15_CTRL_M;
>>> +  arm_cp15_set_control(ctrl);
>>>   }
>>
>>
>> I would rather fix the driver. Add cache flush/invalidate calls to the right
>> spots or use a non-cacheable memory area, see
>> rtems_cache_coherent_allocate() for example.
>>
>> --
>> Sebastian Huber, embedded brains GmbH
>>
>> Address : Dornierstr. 4, D-82178 Puchheim, Germany
>> Phone   : +49 89 189 47 41-16
>> Fax     : +49 89 189 47 41-09
>> E-Mail  : sebastian.huber at embedded-brains.de
>> PGP     : Public key available on request.
>>
>> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.
>>
>
>
>
> --
> ragu



-- 
ragu