[PATCH v4 03/12] omap_hsmmc: add support for pre_req and post_req

[per.forlin@linaro.org (Per Forlin)]

On 16 June 2011 15:14, S, Venkatraman <svenkatr@ti.com> wrote:
> On Thu, May 26, 2011 at 3:27 AM, Per Forlin <per.forlin@linaro.org> wrote:
>> pre_req() runs dma_map_sg(), post_req() runs dma_unmap_sg.
>> If not calling pre_req() before omap_hsmmc_request()
>> dma_map_sg will be issued before starting the transfer.
>> It is optional to use pre_req(). If issuing pre_req()
>> post_req() must be to be called as well.
>>
>> Signed-off-by: Per Forlin <per.forlin@linaro.org>
>> ---
>> ?drivers/mmc/host/omap_hsmmc.c | ? 87 +++++++++++++++++++++++++++++++++++++++--
>> ?1 files changed, 83 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
>> index ad3731a..2116c09 100644
>> --- a/drivers/mmc/host/omap_hsmmc.c
>> +++ b/drivers/mmc/host/omap_hsmmc.c
>> @@ -141,6 +141,11 @@
>> ?#define OMAP_HSMMC_WRITE(base, reg, val) \
>> ? ? ? ?__raw_writel((val), (base) + OMAP_HSMMC_##reg)
>>
>> +struct omap_hsmmc_next {
>> + ? ? ? unsigned int ? ?dma_len;
>> + ? ? ? s32 ? ? ? ? ? ? cookie;
>> +};
>> +
>> ?struct omap_hsmmc_host {
>> ? ? ? ?struct ?device ? ? ? ? ?*dev;
>> ? ? ? ?struct ?mmc_host ? ? ? ?*mmc;
>> @@ -184,6 +189,7 @@ struct omap_hsmmc_host {
>> ? ? ? ?int ? ? ? ? ? ? ? ? ? ? reqs_blocked;
>> ? ? ? ?int ? ? ? ? ? ? ? ? ? ? use_reg;
>> ? ? ? ?int ? ? ? ? ? ? ? ? ? ? req_in_progress;
>> + ? ? ? struct omap_hsmmc_next ?next_data;
>>
>> ? ? ? ?struct ?omap_mmc_platform_data ?*pdata;
>> ?};
>> @@ -1344,8 +1350,9 @@ static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *cb_data)
>> ? ? ? ? ? ? ? ?return;
>> ? ? ? ?}
>>
>> - ? ? ? dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
>> - ? ? ? ? ? ? ? omap_hsmmc_get_dma_dir(host, data));
>> + ? ? ? if (!data->host_cookie)
>> + ? ? ? ? ? ? ? dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ?omap_hsmmc_get_dma_dir(host, data));
>>
>> ? ? ? ?req_in_progress = host->req_in_progress;
>> ? ? ? ?dma_ch = host->dma_ch;
>> @@ -1363,6 +1370,45 @@ static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *cb_data)
>> ? ? ? ?}
>> ?}
>>
>> +static int omap_hsmmc_pre_dma_transfer(struct omap_hsmmc_host *host,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct mmc_data *data,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct omap_hsmmc_next *next)
>> +{
>
> As you are passing &host->next_data into next, next will always be a
> valid pointer. So..
>
omap_hsmmc_pre_dma_transfer() is called from two places. in pre_req()
and start_dma_transfer().
next is NULL if called from start_dma_transfer.

/Per