On Wed, Aug 09, 2017 at 08:29:26PM +0200, Wolfram Sang wrote:
> Make use of the 64 bit sdbuf width on Renesas R-Car Gen3. If the
> registers are 8 byte apart, the width is also 64 bit. For all others,
> the width is 32 bit, even if the registers are only 16 bit apart.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> ---
>
> Change since v1:
> * width calculation is now fully backwards compatible. If it is not 8 byte
> apart (which is only on Gen3), we will always default to 32 as before.
> Thanks to Biju Das and Simon Horman for the error reports!
>
> Tested on a M3-W Salvator-X and H2 Lager (with both SDHI instances). On
> the Lager, I could reproduce the problem with the old patch. It is gone now!
Do you think there is any value in widening the test-coverage of this
change, f.e. to older SoCs?
> drivers/mmc/host/renesas_sdhi_core.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
> index dd215723fa4312..a252145097d6a5 100644
> --- a/drivers/mmc/host/renesas_sdhi_core.c
> +++ b/drivers/mmc/host/renesas_sdhi_core.c
> @@ -459,10 +459,11 @@ static int renesas_sdhi_multi_io_quirk(struct mmc_card *card,
>
> static void renesas_sdhi_enable_dma(struct tmio_mmc_host *host, bool enable)
> {
> - sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? DMA_ENABLE_DMASDRW : 0);
> + /* Iff regs are 8 byte apart, sdbuf is 64 bit. Otherwise always 32. */
> + int width = (host->bus_shift == 2) ? 64 : 32;
>
> - /* enable 32bit access if DMA mode if possibile */
> - renesas_sdhi_sdbuf_width(host, enable ? 32 : 16);
> + sd_ctrl_write16(host, CTL_DMA_ENABLE, enable ? DMA_ENABLE_DMASDRW : 0);
> + renesas_sdhi_sdbuf_width(host, enable ? width : 16);
> }
>
> int renesas_sdhi_probe(struct platform_device *pdev,
> --
> 2.11.0
>
