Re: [PATCH v2 01/12] mmc: add none blocking mmc request function

From: David Vrabel
Date: Fri Apr 15 2011 - 06:35:23 EST

On 06/04/11 20:07, Per Forlin wrote:
> Previously there has only been one function mmc_wait_for_req
> to start and wait for a request. This patch adds
> * mmc_start_req - starts a request wihtout waiting
> * mmc_wait_for_req_done - waits until request is done
> * mmc_pre_req - asks the host driver to prepare for the next job
> * mmc_post_req - asks the host driver to clean up after a completed job

If MMC core had a queue of requests internally you wouldn't need to
provide mmc_pre_req() and mmc_post_req() functions outside of the core.
i.e., the mmc block driver would just need to queue up two mmc requests
and the core would take care of calling pre_req and post_req at the
correct time.

Using a MMC request queue has other benefits -- it allows multiple users
without having to claim/release the host. This would be useful for
(especially multi-function) SDIO.

David Vrabel, Senior Software Engineer, Drivers
CSR, Churchill House, Cambridge Business Park, Tel: +44 (0)1223 692562
Cowley Road, Cambridge, CB4 0WZ

Member of the CSR plc group of companies. CSR plc registered in England and Wales, registered number 4187346, registered office Churchill House, Cambridge Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom
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