From 82f72b96de81478fb5d627be30a2f81ef2c5135f Mon Sep 17 00:00:00 2001 From: px4dev Date: Fri, 25 Jan 2013 21:35:32 -0800 Subject: Move DMA start for tx/rx into the gap where SCL is still stretched so that there is no risk of receiving the first byte before DMA starts. --- apps/px4io/i2c.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'apps/px4io') diff --git a/apps/px4io/i2c.c b/apps/px4io/i2c.c index 174ec2813..bbb72360b 100644 --- a/apps/px4io/i2c.c +++ b/apps/px4io/i2c.c @@ -158,6 +158,9 @@ i2c_interrupt(int irq, FAR void *context) if (sr1 & I2C_SR1_ADDR) { + stm32_dmastart(tx_dma, NULL, NULL, false); + stm32_dmastart(rx_dma, NULL, NULL, false); + /* clear ADDR to ack our selection and get direction */ (void)rSR1; /* as recommended, re-read SR1 */ uint16_t sr2 = rSR2; @@ -166,13 +169,11 @@ i2c_interrupt(int irq, FAR void *context) /* we are the transmitter */ direction = DIR_TX; - stm32_dmastart(tx_dma, NULL, NULL, false); } else { /* we are the receiver */ direction = DIR_RX; - stm32_dmastart(rx_dma, NULL, NULL, false); } } -- cgit v1.2.3