From: Tim Ousley <tim.ousley@ni.com>
Date: Sat, 28 Jul 2001 19:48:01 +0000 (+0000)
Subject: MITE DMA works with any size acquisition and any size buffer, although
X-Git-Tag: r0_7_61~214
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=62b05e33cdd055a2d2e5c034fc373d899cfda58e;p=comedi.git

MITE DMA works with any size acquisition and any size buffer, although
large buffers are still best.
---

diff --git a/comedi/drivers/mite.c b/comedi/drivers/mite.c
index 86abb68c..6a259f6e 100644
--- a/comedi/drivers/mite.c
+++ b/comedi/drivers/mite.c
@@ -150,7 +150,7 @@ int mite_setup(struct mite_struct *mite)
 #if LINUX_VERSION_CODE < 0x020300
 	addr=mite->pcidev->base_address[0];
 #else
-	pci_enable_device(mite->pcidev);
+	//pci_enable_device(mite->pcidev);  This is causing a hang when used with PCIDMA -- 7/27/01 Tim
 	addr=mite->pcidev->resource[0].start;
 #endif
 #endif
@@ -293,9 +293,9 @@ void mite_dma_prep(struct mite_struct *mite,comedi_subdevice *s)
  * Create the short linkchaining MITE linked list using kernel memory
  * a drop in replacement for mite_ll_from_user( ) 
  */
-unsigned long mite_ll_from_kvmem(struct mite_struct *mite,comedi_async *async,int len)
+unsigned long mite_ll_from_kvmem(struct mite_struct *mite,comedi_async *async,int reqlen)
 {
-	int i,size_so_far, continuous_aq;
+	int i,size_so_far, continuous_aq, len;
 	unsigned long nup;
 	unsigned long prealloc_buf,prealloc_bufsz; 
 	//comedi_subdevice *s;
@@ -312,11 +312,14 @@ unsigned long mite_ll_from_kvmem(struct mite_struct *mite,comedi_async *async,in
 	continuous_aq = (async->cmd.stop_src == TRIG_NONE? 1:0);
 	if(continuous_aq) {
 		len = prealloc_bufsz;
+	}else{
+		len = (reqlen>prealloc_bufsz?prealloc_bufsz:reqlen);
 	}
 	
-	if(async->data_len<len) {
-		printk("<1>Comedi Error: preallocated DMA buffer is too small to hold the samples.");
-	}
+	//if(async->data_len<len) {
+	//	printk("<1>Comedi Error: preallocated DMA buffer is too small to hold the samples.");
+	//}
+	
 	//find the kernel's memory pages.
 	nup = (unsigned long)async->data;
 	i=0;
@@ -340,9 +343,15 @@ unsigned long mite_ll_from_kvmem(struct mite_struct *mite,comedi_async *async,in
 	//mite->ring[i].count=0;
 	
 	if (continuous_aq&&(i>0)) {
-		mite->ring[i-1].next = virt_to_bus(mite->ring+0); 
-	}else {
+		mite->ring[i-1].next = virt_to_bus(mite->ring+0);
+		mite->DMA_CheckNearEnd = 0;
+	}else if (prealloc_bufsz < reqlen) {
+		mite->ring[i-1].next = virt_to_bus(mite->ring+0);
+		mite->DMA_CheckNearEnd = 1;
+	}	
+	else {
 		mite->ring[i].count=0;
+		mite->DMA_CheckNearEnd = 0;
 	}
 
 	
diff --git a/comedi/drivers/mite.h b/comedi/drivers/mite.h
index 61a06f8c..6fefaea5 100644
--- a/comedi/drivers/mite.h
+++ b/comedi/drivers/mite.h
@@ -64,6 +64,8 @@ struct mite_struct{
 	void *mite_io_addr;
 	unsigned long daq_phys_addr;
 	void *daq_io_addr;
+	
+	int DMA_CheckNearEnd;
 
 	struct mite_dma_chain ring[MITE_RING_SIZE];
 };
diff --git a/comedi/drivers/ni_mio_common.c b/comedi/drivers/ni_mio_common.c
index c41b0bc1..63fd009e 100644
--- a/comedi/drivers/ni_mio_common.c
+++ b/comedi/drivers/ni_mio_common.c
@@ -328,17 +328,19 @@ void ni_E_interrupt(int irq,void *d,struct pt_regs * regs)
 #ifdef PCIDMA
 static void mite_handle_interrupt(comedi_device *dev,unsigned long m_status)
 {
+	int len;
+	
 	comedi_subdevice *s=dev->subdevices+0;
 	
 	comedi_event(dev,s,COMEDI_CB_BLOCK);
 
 	MDPRINTK("mite_handle_interrupt\n");
 	writel(CHOR_CLRLC, devpriv->mite->mite_io_addr+MITE_CHOR+CHAN_OFFSET(0));
-#if 0
+/*
 	//Don't munge the data, just update the user's status variables
 	s->async->buf_int_count=mite_bytes_transferred(devpriv->mite, 0);
 	s->async->buf_int_ptr= s->async->buf_int_count % s->async->prealloc_bufsz;     
-#else
+*/
 	//Munge the ADC data to change its format from twos complement to unsigned int
 	//This is slow but makes it more compatible with other cards
 	{ 
@@ -354,7 +356,27 @@ static void mite_handle_interrupt(comedi_device *dev,unsigned long m_status)
 		raw_ptr+s->async->prealloc_buf);
 	s->async->buf_int_ptr = raw_ptr;
 	}
-#endif
+
+
+	len = sizeof(sampl_t)*s->async->cmd.stop_arg*s->async->cmd.scan_end_arg;
+	if((devpriv->mite->DMA_CheckNearEnd)&&
+			(s->async->buf_int_count > (len - s->async->prealloc_bufsz))) {
+		long offset;
+		int i;
+		
+		offset = len % s->async->prealloc_bufsz;
+		if(offset < devpriv->mite->ring[0].count) {
+			devpriv->mite->ring[0].count = offset;
+			devpriv->mite->ring[1].count = 0;
+		}else{
+			offset -= devpriv->mite->ring[0].count;
+			i = offset / PAGE_SIZE;
+			devpriv->mite->ring[i].count = offset % PAGE_SIZE;
+			devpriv->mite->ring[(i+1)%MITE_RING_SIZE].count = 0;			
+		}
+		devpriv->mite->DMA_CheckNearEnd = 0;		
+	}
+
 	MDPRINTK("CHSR is 0x%08lx, count is %d\n",m_status,s->async->buf_int_count);
 	if(m_status&CHSR_DONE){
 		writel(CHOR_CLRDONE, devpriv->mite->mite_io_addr+MITE_CHOR+CHAN_OFFSET(0));
@@ -735,10 +757,7 @@ int ni_ai_setup_block_dma(comedi_device *dev,int frob,int mode1)
 	        
 	MDPRINTK("ni_ai_setup_block_dma\n");
 	        
-	/*Build MITE linked list and configure the MITE
-	 * ******WARNING******
-	 * There is no error handling here, 
-	 * the memory buffer *Must* be mlock'ed by the user*/
+	/*Build MITE linked list and configure the MITE*/
 
 	len = sizeof(sampl_t)*cmd->stop_arg*cmd->scan_end_arg;