From: CMY <cmy@rock-chips.com>
Date: Mon, 21 Jul 2014 10:18:36 +0000 (+0800)
Subject: rk: cma: attempt to allocate same range memory while cma allocation failure
X-Git-Tag: firefly_0821_release~4958
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=17beed5e65b338169ff45cfc6f9c4f28f86b3899;p=firefly-linux-kernel-4.4.55.git

rk: cma: attempt to allocate same range memory while cma allocation failure
---

diff --git a/arch/arm/configs/rockchip_defconfig b/arch/arm/configs/rockchip_defconfig
index 00c4bb505c8b..994680bae324 100644
--- a/arch/arm/configs/rockchip_defconfig
+++ b/arch/arm/configs/rockchip_defconfig
@@ -209,6 +209,7 @@ CONFIG_RFKILL=y
 CONFIG_RFKILL_RK=y
 CONFIG_DEVTMPFS=y
 CONFIG_DMA_CMA=y
+CONFIG_CMA_ALLOC_RETRY=20
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_UID_STAT=y
 CONFIG_SRAM=y
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 10cd80af2aec..5f58056429e6 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -278,6 +278,14 @@ config CMA_AREAS
 
 	  If unsure, leave the default value "7".
 
+config CMA_ALLOC_RETRY
+	int "Maximum count to retry of the CMA Allocation"
+	depends on ARCH_ROCKCHIP
+	default 20
+	help
+	  CMA allocation range may be busy at this time, we can try again a few
+	  time to make allocate successful.
+
 endif
 
 endmenu
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 99802d6f3c60..3bf898d5f866 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -297,12 +297,18 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
 	mutex_lock(&cma_mutex);
 
 	for (;;) {
+#ifdef CONFIG_CMA_ALLOC_RETRY
+		int retry = 0;
+#endif
 		pageno = bitmap_find_next_zero_area(cma->bitmap, cma->count,
 						    start, count, mask);
 		if (pageno >= cma->count)
 			break;
 
 		pfn = cma->base_pfn + pageno;
+#ifdef CONFIG_CMA_ALLOC_RETRY
+		do {
+#endif
 		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA);
 		if (ret == 0) {
 			bitmap_set(cma->bitmap, pageno, count);
@@ -311,6 +317,12 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
 		} else if (ret != -EBUSY) {
 			break;
 		}
+#ifdef CONFIG_CMA_ALLOC_RETRY
+		}while (++retry<=CONFIG_CMA_ALLOC_RETRY);
+
+		if (retry<=CONFIG_CMA_ALLOC_RETRY)
+			break;
+#endif
 		pr_debug("%s(): memory range at %p is busy, retrying\n",
 			 __func__, pfn_to_page(pfn));
 		/* try again with a bit different memory target */