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LPC17: Fix a critical error in GPDMA reported by Lizhuoyi

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This commit is contained in:
Gregory Nutt 2014-06-06 11:20:28 -06:00
parent 39cf9e248b
commit dc32678da1
1 changed files with 13 additions and 4 deletions
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17
arch/arm/src/lpc17xx/lpc17_gpdma.c
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@ -1,7 +1,7 @@
/****************************************************************************
* arch/arm/src/lpc17xx/lpc17_gpdma.c
*
* Copyright (C) 2010 Gregory Nutt. All rights reserved.
* Copyright (C) 2010, 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -73,6 +73,7 @@ struct lpc17_dmach_s
uint8_t chn; /* The DMA channel number */
bool inuse; /* True: The channel is in use */
bool inprogress; /* True: DMA is in progress on this channel */
uint16_t nxfrs; /* Number of transfers */
dma_callback_t callback; /* DMA completion callback function */
void *arg; /* Argument to pass to the callback function */
};
@ -464,7 +465,7 @@ int lpc17_dmasetup(DMA_HANDLE handle, uint32_t control, uint32_t config,
uint32_t regval;
uint32_t base;
DEBUGASSERT(dmach && dmach->inuse);
DEBUGASSERT(dmach && dmach->inuse && nxfrs < 4096);
chbit = DMACH((uint32_t)dmach->chn);
base = LPC17_DMACH_BASE((uint32_t)dmach->chn);
@ -522,6 +523,10 @@ int lpc17_dmasetup(DMA_HANDLE handle, uint32_t control, uint32_t config,
regval |= ((uint32_t)nxfrs << DMACH_CONTROL_XFRSIZE_SHIFT);
putreg32(regval, base + LPC17_DMACH_CONTROL_OFFSET);
/* Save the number of transfer to perform for lpc17_dmastart */
dmach->nxfrs = (uint16_t)nxfrs;
/* 7. "Write the channel configuration information into the DMACCxConfig
* register. If the enable bit is set then the DMA channel is
* automatically enabled."
@ -573,11 +578,15 @@ int lpc17_dmastart(DMA_HANDLE handle, dma_callback_t callback, void *arg)
putreg32(chbit, LPC17_DMA_INTTCCLR);
putreg32(chbit, LPC17_DMA_INTERRCLR);
/* Enable terminal count interrupt */
/* Enable terminal count interrupt. Note that we need to restore the
* number transfers. That is because the value has a different meaning
* when it is read.
*/
base = LPC17_DMACH_BASE((uint32_t)dmach->chn);
regval = getreg32(base + LPC17_DMACH_CONTROL_OFFSET);
regval |= DMACH_CONTROL_I;
regval &= ~DMACH_CONTROL_XFRSIZE_MASK;
regval |= (DMACH_CONTROL_I | ((uint32_t)dmach->nxfrs << DMACH_CONTROL_XFRSIZE_SHIFT));
putreg32(regval, base + LPC17_DMACH_CONTROL_OFFSET);
/* Enable the channel and unmask terminal count and error interrupts.