bcm2835-sdhost: Allow for sg entries that cross pages

The dma_complete handling code calculates a virtual address for a page then adds an offset, but if the offset is more than a page and HIGHMEM is in use then the summed address could be in an unmapped (or just incorrect) page. The upstream SDHOST driver allows for this possibility - copy the code that does so. Signed-off-by: Phil Elwell <[email protected]>
raspberrypi · Mar 21, 2019 · 5b12bd4 · 5b12bd4
1 parent 3111886
commit 5b12bd4
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/mmc/host/bcm2835-sdhost.c b/drivers/mmc/host/bcm2835-sdhost.c
@@ -543,6 +543,11 @@ static void bcm2835_sdhost_dma_complete(void *param)
 		void *page;
 		u32 *buf;
 
+		if (host->drain_offset & PAGE_MASK) {
+			host->drain_page += host->drain_offset >> PAGE_SHIFT;
+			host->drain_offset &= ~PAGE_MASK;
+		}
+
 		page = kmap_atomic(host->drain_page);
 		buf = page + host->drain_offset;