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| author | Gregory Nutt <gnutt@nuttx.org> | 2015-01-08 06:23:42 -0600 |
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| committer | Gregory Nutt <gnutt@nuttx.org> | 2015-01-08 06:23:42 -0600 |
| commit | 3cfb3001c68d449f0b59586bca112bf5a2e226fa (patch) | |
| tree | 6b44391374480c4fd0210992945de74f35b85e64 /nuttx/include/syscall.h | |
| parent | 982650a1b30076732fee025a63ec151fc0f3dcb1 (diff) | |
| download | px4-nuttx-3cfb3001c68d449f0b59586bca112bf5a2e226fa.tar.gz px4-nuttx-3cfb3001c68d449f0b59586bca112bf5a2e226fa.tar.bz2 px4-nuttx-3cfb3001c68d449f0b59586bca112bf5a2e226fa.zip | |
MMCSD SDIO: Add support for a new SDWAIT_WRCOMPLETE condition. The previous logic used a busy-wait loop to pool the card R1 start to determine when the card was ready for the next transfer. That busy-wait can be quite long -- hundreds of milliseconds. And alternative is to look the the SD D0 pin which will change state when the card is no longer busy.
This logic implements a change the avoids the busy-wait poll by reconfiguring the SD D0 pin as a GPIO interrupt, then waiting for the card to becom ready without taking up CPU cycles.
This change is conditioned on CONFIG_MMCSD_SDIOWATI_WRCOMPLETE and is currenlty only implemented for the STM32 SDIO driver.
From David Sidrane
Diffstat (limited to 'nuttx/include/syscall.h')
0 files changed, 0 insertions, 0 deletions