> On November 22, 2019 at 7:13 AM Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> wrote:
>
>
> Falling back to PIO forever is not convenience if a buffer condition
> is not match with the hardware once. So, this patch removes it.
>
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> ---
> drivers/mmc/host/renesas_sdhi_sys_dmac.c | 35 +++++++-------------------------
> 1 file changed, 7 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> index 30f34a3..09137cc 100644
> --- a/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> +++ b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> @@ -175,7 +175,7 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
> }
>
> if (sg->length < min_len)
> - return;
> + goto pio;
>
> /* The only sg element can be unaligned, use our bounce buffer then */
> if (!aligned) {
> @@ -200,23 +200,13 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
> ret = cookie;
> }
> host->dma_on = true;
> + renesas_sdhi_sys_dmac_enable_dma(host, true);
> }
> pio:
> if (!desc) {
> - /* DMA failed, fall back to PIO */
> renesas_sdhi_sys_dmac_enable_dma(host, false);
> - if (ret >= 0)
> - ret = -EIO;
> - host->chan_rx = NULL;
> - dma_release_channel(chan);
> - /* Free the Tx channel too */
> - chan = host->chan_tx;
> - if (chan) {
> - host->chan_tx = NULL;
> - dma_release_channel(chan);
> - }
> - dev_warn(&host->pdev->dev,
> - "DMA failed: %d, falling back to PIO\n", ret);
> + host->dma_on = false;
> + dev_dbg(&host->pdev->dev, "DMA failed: %d\n", ret);
> }
> }
>
> @@ -248,7 +238,7 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
> }
>
> if (sg->length < min_len)
> - return;
> + goto pio;
>
> /* The only sg element can be unaligned, use our bounce buffer then */
> if (!aligned) {
> @@ -281,20 +271,9 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
> }
> pio:
> if (!desc) {
> - /* DMA failed, fall back to PIO */
> renesas_sdhi_sys_dmac_enable_dma(host, false);
> - if (ret >= 0)
> - ret = -EIO;
> - host->chan_tx = NULL;
> - dma_release_channel(chan);
> - /* Free the Rx channel too */
> - chan = host->chan_rx;
> - if (chan) {
> - host->chan_rx = NULL;
> - dma_release_channel(chan);
> - }
> - dev_warn(&host->pdev->dev,
> - "DMA failed: %d, falling back to PIO\n", ret);
> + host->dma_on = false;
> + dev_dbg(&host->pdev->dev, "DMA failed: %d\n", ret);
> }
> }
>
> --
> 2.7.4
Reviewed-by: Ulrich Hecht <uli+renesas@xxxxxxxx>
CU
Uli
