mmc: tmio: simplify the DMA mode test

host->chan_{rx,tx} represents the DMA capability of the platform.
Even if DMA is supported, there are cases where we want to use PIO,
for example, data length is short enough as commit 5f52c3552946
("mmc: tmio: use PIO for short transfers") mentioned.

Regarding the hardware control flow, we are interested in whether DMA
is currently enabled or not, instead of whether the platform has the
DMA capability.

Hence, the several conditionals in tmio_mmc_core.c end up with
checking host->chan_{rx,tx} and !host->force_pio. This is not nice.

Let's flip the flag host->force_pio into host->dma_on.

host->dma_on represents whether the DMA is currently enabled or not.
This flag is set false in the beginning of each command, then should
be set true by tmio_mmc_start_dma() when the DMA is turned on.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
index 40fa0a88208d..8d64f6196f33 100644
--- a/drivers/mmc/host/tmio_mmc_core.c
+++ b/drivers/mmc/host/tmio_mmc_core.c
@@ -361,7 +361,7 @@ static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
 	unsigned int count;
 	unsigned long flags;
 
-	if ((host->chan_tx || host->chan_rx) && !host->force_pio) {
+	if (host->dma_on) {
 		pr_err("PIO IRQ in DMA mode!\n");
 		return;
 	} else if (!data) {
@@ -433,7 +433,7 @@ void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
 	 */
 
 	if (data->flags & MMC_DATA_READ) {
-		if (host->chan_rx && !host->force_pio)
+		if (host->dma_on)
 			tmio_mmc_check_bounce_buffer(host);
 		dev_dbg(&host->pdev->dev, "Complete Rx request %p\n",
 			host->mrq);
@@ -470,7 +470,7 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
 	if (stat & TMIO_STAT_CRCFAIL || stat & TMIO_STAT_STOPBIT_ERR ||
 	    stat & TMIO_STAT_TXUNDERRUN)
 		data->error = -EILSEQ;
-	if (host->chan_tx && (data->flags & MMC_DATA_WRITE) && !host->force_pio) {
+	if (host->dma_on && (data->flags & MMC_DATA_WRITE)) {
 		u32 status = sd_ctrl_read16_and_16_as_32(host, CTL_STATUS);
 		bool done = false;
 
@@ -494,7 +494,7 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
 			tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
 			tmio_mmc_dataend_dma(host);
 		}
-	} else if (host->chan_rx && (data->flags & MMC_DATA_READ) && !host->force_pio) {
+	} else if (host->dma_on && (data->flags & MMC_DATA_READ)) {
 		tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
 		tmio_mmc_dataend_dma(host);
 	} else {
@@ -547,7 +547,7 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
 	 */
 	if (host->data && (!cmd->error || cmd->error == -EILSEQ)) {
 		if (host->data->flags & MMC_DATA_READ) {
-			if (host->force_pio || !host->chan_rx) {
+			if (!host->dma_on) {
 				tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_READOP);
 			} else {
 				tmio_mmc_disable_mmc_irqs(host,
@@ -555,7 +555,7 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
 				tasklet_schedule(&host->dma_issue);
 			}
 		} else {
-			if (host->force_pio || !host->chan_tx) {
+			if (!host->dma_on) {
 				tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_WRITEOP);
 			} else {
 				tmio_mmc_disable_mmc_irqs(host,
@@ -685,7 +685,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
 
 	tmio_mmc_init_sg(host, data);
 	host->data = data;
-	host->force_pio = false;
+	host->dma_on = false;
 
 	/* Set transfer length / blocksize */
 	sd_ctrl_write16(host, CTL_SD_XFER_LEN, data->blksz);