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