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

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

[Ley Foon Tan]

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@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

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

[Jaehoon Chung]

On 4/26/21 12:35 PM, Ley Foon Tan wrote:
> 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@intel.com>

Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

Best Regards,
Jaehoon Chung

> ---
>  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) {
>