Re: [PATCH] dma: fix scope of errata i88 upto 3430ES1.0

[Venkatraman S <svenkatr@ti.com>]

On Mon, Apr 5, 2010 at 7:56 PM, Shilimkar, Santosh
<santosh.shilimkar@ti.com> wrote:
> Venkat,
>> -----Original Message-----
>> From: svenkatr@gmail.com [mailto:svenkatr@gmail.com] On Behalf Of S, Venkatraman
>> Sent: Friday, April 02, 2010 5:05 PM
>> To: linux-omap@vger.kernel.org
>> Cc: Gopinath, Thara; Tony Lindgren; Shilimkar, Santosh
>> Subject: [PATCH] dma: fix scope of errata i88 upto 3430ES1.0
>>
>> DMA errata for special end of block programming is applicable
>> only for OMAP2430 & OMAP3430 ES1.0.
>> This patch does the necessary checks before the workaround
>> is applied. Tested on 3430 SDP
>>
>> Signed-off-by: Thara Gopinath <thara@ti.com>
>> Signed-off-by: Venkatraman S <svenkatr@ti.com>
>> ---
>>  arch/arm/plat-omap/dma.c |   22 ++++++++++++++--------
>>  1 files changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
>> index 2ab224c..ef965ac 100644
>> --- a/arch/arm/plat-omap/dma.c
>> +++ b/arch/arm/plat-omap/dma.c
>> @@ -1663,14 +1663,18 @@ int omap_stop_dma_chain_transfers(int chain_id)
>>       channels = dma_linked_lch[chain_id].linked_dmach_q;
>>
>>       /*
>> -      * DMA Errata:
>> -      * Special programming model needed to disable DMA before end of block
>> +      * DMA Errata: i88
>> +      * Special programming model needed
>> +      * to disable DMA before end of block
>>        */
>>       sys_cf = dma_read(OCP_SYSCONFIG);
>> -     l = sys_cf;
>> -     /* Middle mode reg set no Standby */
>> -     l &= ~((1 << 12)|(1 << 13));
>> -     dma_write(l, OCP_SYSCONFIG);
>> +     if (cpu_is_omap2430() || (cpu_is_omap3430() &&
>> +                     omap_rev() == OMAP3430_REV_ES1_0)) {
> Since the Errata is applicable only for "omap2430" and
> "OMAP3430 ES1.0", below should be enough, isn't it ?
>
> if (cpu_is_omap2430() || omap_rev() == OMAP3430_REV_ES1_0))

Yup.. Looks simpler. I will update.

>> +             l = sys_cf;
>> +             /* Middle mode reg set no Standby */
>> +             l &= ~((1 << 12)|(1 << 13));
>> +             dma_write(l, OCP_SYSCONFIG);
>> +     }
>>
>>       for (i = 0; i < dma_linked_lch[chain_id].no_of_lchs_linked; i++) {
>>
>> @@ -1689,8 +1693,10 @@ int omap_stop_dma_chain_transfers(int chain_id)
>>       /* Reset the Queue pointers */
>>       OMAP_DMA_CHAIN_QINIT(chain_id);
>>
>> -     /* Errata - put in the old value */
>> -     dma_write(sys_cf, OCP_SYSCONFIG);
>> +     /* Errata: put back the old value */
>> +     if (cpu_is_omap2430() || (cpu_is_omap3430() &&
>> +                     omap_rev() == OMAP3430_REV_ES1_0))
> Same as above comment.
>> +             dma_write(sys_cf, OCP_SYSCONFIG);
>>
>>       return 0;
>>  }
> After fixing above two, the patch is fine with me.

Thanks, I take that as ack ? :-)
Regards,
Venkat.
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