diff options
| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2018-10-12 18:03:08 +0300 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2018-10-15 15:52:50 +0300 |
| commit | d3dd5db0c1b904e71690ef8cfaebd562d8e865b1 (patch) | |
| tree | bf15a44ac594b9d85d402df1b7269cd3471603b8 /drivers/mmc/host/renesas_sdhi_sys_dmac.c | |
| parent | 722fb61e2ed39473297157839ec7230b77fd6940 (diff) | |
| download | linux-d3dd5db0c1b904e71690ef8cfaebd562d8e865b1.tar.xz | |
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>
Diffstat (limited to 'drivers/mmc/host/renesas_sdhi_sys_dmac.c')
| -rw-r--r-- | drivers/mmc/host/renesas_sdhi_sys_dmac.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c index f027f66fe0c1..1a4016f635d3 100644 --- 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) { |