diff options
| author | Ryan QIAN <b32804@freescale.com> | 2012-07-25 13:58:46 +0800 |
|---|---|---|
| committer | Ryan QIAN <b32804@freescale.com> | 2012-07-26 11:09:35 +0800 |
| commit | f63a8292fe128987ea4f8ab695f08a7fd9ea69bc (patch) | |
| tree | 7d9126fdc6f034e9d8eca3fbfc65ef65c7f72032 /drivers/mmc | |
| parent | ad373c687c56cd1a8e8c47e00b1a07deb84c6310 (diff) | |
ENGR00215346: mmc: esdhc: change to use sdma instead of adma due to ic limit.
Due to ic issue, adma2 failed to work when ahb freq is slow (<50Mhz),
while SDMA does not have issue.
workaround:
- use SDMA instead.
performance comparison between SDMA & ADMA:
| | SDMA | ADMA |
---------------------------------------------------------------------
| wifi downlink* | ~38Mbps | ~38Mbps |
| memory card** | ~20MBps(r)/~4MBps(w) | ~20MBps(r)/~9MBps(w) |
* wifi downlink throughput is tested by iperf in open air.
** writing performance for SDMA is much slower than ADMA, it might
be an issue which needs further investigation.
Signed-off-by: Ryan QIAN <b32804@freescale.com>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/host/sdhci-esdhc-imx.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 3f809a6c87f3..7beb8b9323bc 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -957,6 +957,7 @@ struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = { .quirks = ESDHC_DEFAULT_QUIRKS | SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC | SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC | SDHCI_QUIRK_BROKEN_CARD_DETECTION + | SDHCI_QUIRK_BROKEN_ADMA | SDHCI_QUIRK_NO_HISPD_BIT, /* ADMA has issues. Might be fixable */ .ops = &sdhci_esdhc_ops, |