Subject: [PATCH v2] ARM: EDMA: Fix clearing of unused list for DT DMA resources

From: [email-masked] (Mark Jackson)
Date: Fri, 06 Sep 2013 20:15:27 +0100

On 06/09/13 20:13, Mark Jackson wrote:
> On 23/08/13 20:53, Joel Fernandes wrote:
>> HWMOD removal for MMC and Crypto is breaking edma_start as the events are
>> being manually triggered due to unused channel list not being clear. Atleast
>> breakage has been seen on these peripherals, but it is expected Audio (McASP)
>> maybe breaking too.
>>
>> This patch fixes the issue, by reading the "dmas" property from the DT node if
>> it exists and clearing the bits in the unused channel list so that these channels
>> are not manually triggered.
>>
>> v2 changes:
>> Reduced indendation by returning from if block.
>>
>> Reviewed-by: Sekhar Nori <[email-masked]>
>> Reported-by: Balaji T K <[email-masked]>
>> Cc: Pantel Antoniou <[email-masked]>
>> Signed-off-by: Joel Fernandes <[email-masked]>
>> ---
>> Note:
>> Patch should go in for -rc cycle as it fixes existing crypto drivers.
>>
>>  arch/arm/common/edma.c | 22 +++++++++++++++++++---
>>  1 file changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
>> index 39ad030..3867e7e 100644
>> --- a/arch/arm/common/edma.c
>> +++ b/arch/arm/common/edma.c
>> @@ -560,14 +560,30 @@ static int reserve_contiguous_slots(int ctlr, unsigned int id,
>>  static int prepare_unused_channel_list(struct device *dev, void *data)
>>  {
>>  	struct platform_device *pdev = to_platform_device(dev);
>> -	int i, ctlr;
>> +	int i = 0, ctlr;
>> +	u32 dma_chan;
>> +	const __be32 *dma_chan_p;
>> +	struct property *prop;
>> +
>> +	if (dev->of_node) {
>> +		of_property_for_each_u32(dev->of_node, "dmas", prop,
>> +					 dma_chan_p, dma_chan) {
>> +			if (i++ & 1) {
>> +				ctlr = EDMA_CTLR(dma_chan);
>> +				clear_bit(EDMA_CHAN_SLOT(dma_chan),
>> +					  edma_cc[ctlr]->edma_unused);
>> +			}
>> +		}
>> +		return;
> 
> This should return something here, otherwise we get:-
> 
> arch/arm/common/edma.c: In function 'prepare_unused_channel_list':
> arch/arm/common/edma.c:577:3: warning: 'return' with no value, in function returning non-void [-Wreturn-type]

Other than that I can confirm it fixes the issue for me ...

Tested-by: Mark Jackson <[email-masked]>