[PATCH v2 5/9] mmc: mediatek: fix got GPD checksum error interrupt when data transfer

From: Chaotian Jing
Date: Tue Oct 20 2015 - 05:18:01 EST


Even if we only use one gpd, we need alloc 2 gpd and make
the gpd->next pointer to the second gpd, or may get gpd checksum
error, this was checked by hardware

Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
---
drivers/mmc/host/mtk-sd.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index c877ded..3858163 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -1145,11 +1145,14 @@ static void msdc_init_gpd_bd(struct msdc_host *host, struct msdc_dma *dma)
struct mt_bdma_desc *bd = dma->bd;
int i;

- memset(gpd, 0, sizeof(struct mt_gpdma_desc));
+ memset(gpd, 0, sizeof(struct mt_gpdma_desc) * 2);

gpd->gpd_info = GPDMA_DESC_BDP; /* hwo, cs, bd pointer */
gpd->ptr = (u32)dma->bd_addr; /* physical address */
-
+ /* gpd->next is must set for desc DMA
+ * That's why must alloc 2 gpd structure.
+ */
+ gpd->next = (u32)dma->gpd_addr + sizeof(struct mt_gpdma_desc);
memset(bd, 0, sizeof(struct mt_bdma_desc) * MAX_BD_NUM);
for (i = 0; i < (MAX_BD_NUM - 1); i++)
bd[i].next = (u32)dma->bd_addr + sizeof(*bd) * (i + 1);
@@ -1306,7 +1309,7 @@ static int msdc_drv_probe(struct platform_device *pdev)

host->timeout_clks = 3 * 1048576;
host->dma.gpd = dma_alloc_coherent(&pdev->dev,
- sizeof(struct mt_gpdma_desc),
+ 2 * sizeof(struct mt_gpdma_desc),
&host->dma.gpd_addr, GFP_KERNEL);
host->dma.bd = dma_alloc_coherent(&pdev->dev,
MAX_BD_NUM * sizeof(struct mt_bdma_desc),
@@ -1347,7 +1350,7 @@ release:
release_mem:
if (host->dma.gpd)
dma_free_coherent(&pdev->dev,
- sizeof(struct mt_gpdma_desc),
+ 2 * sizeof(struct mt_gpdma_desc),
host->dma.gpd, host->dma.gpd_addr);
if (host->dma.bd)
dma_free_coherent(&pdev->dev,
--
1.8.1.1.dirty

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