[PATCH] mmc: dw_mmc: Fixes data read when receiving DTO interrupt in FIFO mode

Ley Foon Tan ley.foon.tan at intel.com
Mon Apr 26 05:35:05 CEST 2021


The data read is not working when using FIFO mode.

>From DesignWare databook, when a Data_Transfer_Over (DTO) interrupt is
received, the software should read the remaining data from FIFO.

Add DTO interrupt checking on data read path and clear interrupts before
start reading from FIFO. So, it doesn't clear the next pending
interrupts unintentionally after read from FIFO.

Signed-off-by: Ley Foon Tan <ley.foon.tan at intel.com>
---
 drivers/mmc/dw_mmc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 7c8a312fa71a..a949dad57402 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -166,7 +166,9 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 		if (host->fifo_mode && size) {
 			len = 0;
 			if (data->flags == MMC_DATA_READ &&
-			    (mask & DWMCI_INTMSK_RXDR)) {
+			    (mask & (DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO))) {
+				dwmci_writel(host, DWMCI_RINTSTS,
+					     DWMCI_INTMSK_RXDR | DWMCI_INTMSK_DTO);
 				while (size) {
 					ret = dwmci_fifo_ready(host,
 							DWMCI_FIFO_EMPTY,
@@ -182,8 +184,6 @@ static int dwmci_data_transfer(struct dwmci_host *host, struct mmc_data *data)
 						dwmci_readl(host, DWMCI_DATA);
 					size = size > len ? (size - len) : 0;
 				}
-				dwmci_writel(host, DWMCI_RINTSTS,
-					     DWMCI_INTMSK_RXDR);
 			} else if (data->flags == MMC_DATA_WRITE &&
 				   (mask & DWMCI_INTMSK_TXDR)) {
 				while (size) {
-- 
2.25.1



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