| title: | Re PATCH 03 03 omap hsmmc adaptation of s |
|
Tony Lindgren wrote:
* Venkatraman S <svenkatr@xxxxxx [100310 06:08]:
@@ -1400,14 +1471,23 @@ omap_hsmmc_prepare_data(struct omap_hsmmc_host
*host, struct mmc_request *req)
| (req- data- blocks << 16));
set_data_timeout(host, req- data- timeout_ns, req- data- timeout_clks);
- if (host- use_dma) {
- ret = omap_hsmmc_start_dma_transfer(host, req);
- if (ret != 0) {
- dev_dbg(mmc_dev(host- mmc), "MMC start dma failure
");
+ if (host- dma_caps & DMA_TYPE_SDMA) {
+ ret = omap_hsmmc_configure_sdma(host, req);
+ if (ret)
return ret;
- }
+ host- dma_in_use = DMA_TYPE_SDMA;
}
- return 0;
+ if ((host- dma_caps & DMA_TYPE_SDMA_DLOAD) &&
+ host- data- sg_len 4) {
+ ret = omap_hsmmc_configure_sdma_sglist(host, req);
+ if (ret)
+ return ret;
+ host- dma_in_use = DMA_TYPE_SDMA_DLOAD;
+
+ }
+ ret = omap_hsmmc_start_dma_transfer(host);
+ return ret;
+
}
Does the driver still work in PIO mode?
We need to have the drivers capable to fail over to PIO mode
as the DMA channels can run out.
The driver doesnt have an automatic fallback to PIO,
even without my patch. A error return from omap_request_dma is
propogated all the way back to the transfer request.
The decision to use_dma (the variable) is unaltered.
Infact, it would be easier to implement a runtime fallback after
this patch is
merged as I have separated out the capability and runtime selection.
(dma_caps and dma_in_use).
Regards,
Venkat.
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