Re: Query regarding ADMA descriptor allocation

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Hi Chris,

Can anyone from SDHCi confirm if the understanding below is correct or not? If it is than we can post a patch to fix it.

Regards,
Subhash

On 1/13/2013 5:50 PM, Asutosh Das wrote:
Hi
Can you please let me know if my understanding in the below question is correct ?

Thanks
Asutosh

On 1/11/2013 6:01 PM, Asutosh Das wrote:
Hi
In sdhci_add_host function, the number of adma descriptors allocated are 128 and each descriptor consumes 8 bytes and 1 4byte is added in the end like,
kmalloc((128 * 2 + 1) * 4, GFP_KERNEL);

In sdhci_adma_table_pre function, each node in sg-list is iterated and in case of a misaligned node, a descriptor is consumed, which means for a single sg-node 2 descriptors were consumed. Let's say in a situation, where there are multiple unaligned addresses in multiple sg nodes and the sg-list length is 128, wouldn't this use up all the 128 descriptors long before the entire sg-list is traversed ?







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