Re: [PATCH V3 3/4] dmaselftest: add memcpy selftest support functions

[Sinan Kaya <okaya@codeaurora.org>]

On 11/8/2015 12:13 AM, Timur Tabi wrote:
> Sinan Kaya wrote:
>
>> +static int dma_selftest_sg(struct dma_device *dmadev,
>> +            struct dma_chan *dma_chanptr, u64 size,
>> +            unsigned long flags)
>> +{
>> +    dma_addr_t src_dma, dest_dma, dest_dma_it;
>> +    u8 *dest_buf;
>> +    u32 i, j = 0;
>> +    dma_cookie_t cookie;
>> +    struct dma_async_tx_descriptor *tx;
>> +    int err = 0;
>> +    int ret;
>> +    struct sg_table sg_table;
>> +    struct scatterlist    *sg;
>> +    int nents = 10, count;
>> +    bool free_channel = 1;
>
> Booleans are either 'true' or 'false'.
>

OK

>> +static int dma_selftest_mapsngle(struct device *dev)
>> +{
>> +    u32 buf_size = 256;
>> +    char *src;
>> +    int ret = -ENOMEM;
>> +    dma_addr_t dma_src;
>> +
>> +    src = kmalloc(buf_size, GFP_KERNEL);
>> +    if (!src)
>> +        return -ENOMEM;
>> +
>> +    strcpy(src, "hello world");
>
> kstrdup()?
>
> And why kmalloc anyway?  Why not leave it on the stack?
>
>      char src[] = "hello world";
>
> ?

I need to call dma_map_single on this address to convert it to a DMA 
address. That's why.

>
>

-- 
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project