From: Frank Mori Hess <fmhess@speakeasy.net>
Date: Tue, 1 May 2007 21:16:15 +0000 (+0000)
Subject: Fixed horrible grinding noises on mmap.
X-Git-Tag: r0_7_74~90
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=29199ca2c2805b7be7b5ec785904a4d4ef9f9ade;p=comedi.git

Fixed horrible grinding noises on mmap.
---

diff --git a/comedi/comedi_fops.c b/comedi/comedi_fops.c
index c54b8ba1..daa4b788 100644
--- a/comedi/comedi_fops.c
+++ b/comedi/comedi_fops.c
@@ -1310,7 +1310,7 @@ static int comedi_mmap(struct file * file, struct vm_area_struct *vma)
 
 	n_pages = size >> PAGE_SHIFT;
 	for(i = 0; i < n_pages; ++i){
-		if(remap_pfn_range(vma, start, page_to_pfn(virt_to_page(async->prealloc_buf + PAGE_SIZE * i)),
+		if(remap_pfn_range(vma, start, page_to_pfn(virt_to_page(async->buf_page_list[i].virt_addr)),
 				PAGE_SIZE, PAGE_SHARED)){
 			return -EAGAIN;
 		}
diff --git a/comedi/drivers.c b/comedi/drivers.c
index 293fdfc4..e96cd2d3 100644
--- a/comedi/drivers.c
+++ b/comedi/drivers.c
@@ -432,25 +432,11 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 	unsigned long new_size)
 {
 	comedi_async *async = s->async;
-	unsigned long adr;
 
 	/* if no change is required, do nothing */
 	if(async->prealloc_buf && async->prealloc_bufsz == new_size){
 		return 0;
 	}
-	// cleanup old buffer
-	if(async->prealloc_bufsz)
-	{
-		int i;
-		unsigned n_pages = async->prealloc_bufsz >> PAGE_SHIFT;
-
-		adr = (unsigned long) async->prealloc_buf;
-		for(i = 0; i < n_pages; i++){
-			mem_map_unreserve(virt_to_page(adr));
-			adr += PAGE_SIZE;
-		}
-		async->prealloc_bufsz = 0;
-	}
 	if(async->prealloc_buf)
 	{
 		if(s->async_dma_dir != DMA_NONE)
@@ -461,6 +447,7 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 			vfree(async->prealloc_buf);
 		}
 		async->prealloc_buf = NULL;
+		async->prealloc_bufsz = 0;
 	}
 	if(async->buf_page_list)
 	{
@@ -468,6 +455,8 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 		for(i = 0; i < async->n_buf_pages; ++i)
 		{
 			if(async->buf_page_list[i].virt_addr)
+				mem_map_unreserve(virt_to_page(async->buf_page_list[i].virt_addr));
+			if(async->buf_page_list[i].dma_addr)
 			{
 				dma_free_coherent(dev->hw_dev, PAGE_SIZE,
 					async->buf_page_list[i].virt_addr, async->buf_page_list[i].dma_addr);
@@ -485,18 +474,18 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 		// size is rounded up to nearest multiple of PAGE_SIZE
 		new_size = n_pages << PAGE_SHIFT;
 
+		async->buf_page_list = vmalloc(sizeof(struct comedi_buf_page) * n_pages);
+		if(async->buf_page_list == NULL)
+		{
+			return -ENOMEM;
+		}
+		memset(async->buf_page_list, 0, sizeof(struct comedi_buf_page) * n_pages);
+		async->n_buf_pages = n_pages;
+
 		if(s->async_dma_dir != DMA_NONE)
 		{
 			struct page** pages = NULL;
 
-			async->buf_page_list = vmalloc(sizeof(struct comedi_buf_page) * n_pages);
-			if(async->buf_page_list == NULL)
-			{
-				return -ENOMEM;
-			}
-			memset(async->buf_page_list, 0, sizeof(struct comedi_buf_page) * n_pages);
-			async->n_buf_pages = n_pages;
-
 			pages = vmalloc(sizeof(struct page*) * n_pages);
 			if(pages == NULL)
 			{
@@ -511,6 +500,7 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 					vfree(pages);
 					return -ENOMEM;
 				}
+				mem_map_reserve(virt_to_page(async->buf_page_list[i].virt_addr));
 				pages[i] = virt_to_page(async->buf_page_list[i].virt_addr);
 			}
 			async->prealloc_buf = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
@@ -523,13 +513,11 @@ int comedi_buf_alloc(comedi_device *dev, comedi_subdevice *s,
 			{
 				return -ENOMEM;
 			}
-		}
-
-		adr = (unsigned long)async->prealloc_buf;
-		for(i = 0; i < n_pages; i++)
-		{
-			mem_map_reserve(virt_to_page(adr));
-			adr += PAGE_SIZE;
+			for(i = 0; i < n_pages; i++)
+			{
+				async->buf_page_list[i].virt_addr = async->prealloc_buf + PAGE_SIZE * i;
+				mem_map_reserve(virt_to_page(async->buf_page_list[i].virt_addr));
+			}
 		}
 	}
 	async->prealloc_bufsz = new_size;
diff --git a/comedi/drivers/mite.c b/comedi/drivers/mite.c
index 6b4f3e82..55d9511a 100644
--- a/comedi/drivers/mite.c
+++ b/comedi/drivers/mite.c
@@ -520,7 +520,7 @@ int mite_sync_output_dma(struct mite_channel *mite_chan, comedi_async *async)
 	u32 nbytes_ub, nbytes_lb;
 	unsigned int old_alloc_count;
 	u32 stop_count = async->cmd.stop_arg * bytes_per_sample(async->subdevice) *
-		async->cmd.chanlist_len;
+		async->cmd.chanlist_len;	//FIXME will be wrong for digital commands
 
 	old_alloc_count = async->buf_read_alloc_count;
 	// read alloc as much as we can