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>

diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index e729c39da83bdd575c6df146a6f7e8d5a09fde3e..b6f54102bfdd3a76c6b77f4c9d62df8ad3c624f6 100644 (file)
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -199,13 +199,14 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
        renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
                                            sg_dma_address(sg));
 
+       host->dma_on = true;
+
        return;
 
 force_pio_with_unmap:
        dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));
 
 force_pio:
-       host->force_pio = true;
        renesas_sdhi_internal_dmac_enable_dma(host, false);
 }
 

diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
index f027f66fe0c1dd97e31b156987e7ae88e2d14c81..1a4016f635d398c28ca9edc5cf202eae6776ffa7 100644 (file)
--- a/drivers/mmc/host/renesas_sdhi_sys_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
@@ -210,10 +210,8 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
                goto pio;
        }
 
-       if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
-               host->force_pio = true;
+       if (sg->length < TMIO_MMC_MIN_DMA_LEN)
                return;
-       }
 
        /* The only sg element can be unaligned, use our bounce buffer then */
        if (!aligned) {
@@ -237,6 +235,7 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
                        desc = NULL;
                        ret = cookie;
                }
+               host->dma_on = true;
        }
 pio:
        if (!desc) {
@@ -283,10 +282,8 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
                goto pio;
        }
 
-       if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
-               host->force_pio = true;
+       if (sg->length < TMIO_MMC_MIN_DMA_LEN)
                return;
-       }
 
        /* The only sg element can be unaligned, use our bounce buffer then */
        if (!aligned) {
@@ -315,6 +312,7 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
                        desc = NULL;
                        ret = cookie;
                }
+               host->dma_on = true;
        }
 pio:
        if (!desc) {

diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index a8ad67eea340ee080a480cc87f2b350d4e3ade90..1e317027bf53461272ea65b9a2b625a8a6519089 100644 (file)
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -138,7 +138,7 @@ struct tmio_mmc_host {
        struct tmio_mmc_data *pdata;
 
        /* DMA support */
-       bool                    force_pio;
+       bool                    dma_on;
        struct dma_chan         *chan_rx;
        struct dma_chan         *chan_tx;
        struct tasklet_struct   dma_issue;

diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
index 40fa0a88208d52b2778401476aec5668528f8f73..8d64f6196f33e882c00c44977090452bd6cf1720 100644 (file)
--- 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);

diff --git a/drivers/mmc/host/uniphier-sd.c b/drivers/mmc/host/uniphier-sd.c
index 10e7b30c792a2cb039a67a97b3cf62461845ff7e..7a8d3081f5790499d48c7efb5ac1f82074fb811a 100644 (file)
--- a/drivers/mmc/host/uniphier-sd.c
+++ b/drivers/mmc/host/uniphier-sd.c
@@ -157,13 +157,14 @@ static void uniphier_sd_external_dma_start(struct tmio_mmc_host *host,
        if (cookie < 0)
                goto unmap_sg;
 
+       host->dma_on = true;
+
        return;
 
 unmap_sg:
        dma_unmap_sg(mmc_dev(host->mmc), host->sg_ptr, host->sg_len,
                     priv->dma_dir);
 force_pio:
-       host->force_pio = true;
        uniphier_sd_dma_endisable(host, 0);
 }
 
@@ -280,9 +281,10 @@ static void uniphier_sd_internal_dma_start(struct tmio_mmc_host *host,
        writel(lower_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_L);
        writel(upper_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_H);
 
+       host->dma_on = true;
+
        return;
 force_pio:
-       host->force_pio = true;
        uniphier_sd_dma_endisable(host, 0);
 }