On 11/20/21 12:53 AM, Mårten Lindahl wrote:
> The TMOUT register is always set with a full value for every transfer,
> which (with a 200MHz clock) will give a full DRTO of ~84 milliseconds.
> This is normally good enough to complete the request, but setting a full
> value makes it impossible to test shorter timeouts, when for example
> testing data read times on different SD cards.
>
> Add a function to set any value smaller than the maximum of 0xFFFFFF.
>
> Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
Reviewed-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
Best Regards,
Jaehoon Chung
> ---
>
> v2:
> - Calculate new value before checking boundaries
> - Include CLKDIV register to get proper value
>
> v3:
> - Use 'if-else' instead of 'goto'
> - Don't touch response field when maximize data field
>
> v4:
> - Prevent 32bit divider overflow by splitting the operation
> - Changed %06x to %#08x as suggested by Doug
> - Rephrased commit msg as suggested by Doug
>
> v5:
> - Use u32 type for CPU reg access
> - Make tmp 64bit to handle INT_MAX parameters
>
> v6:
> - Use u64 type for tmp
>
> drivers/mmc/host/dw_mmc.c | 29 ++++++++++++++++++++++++++++-
> 1 file changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index d977f34f6b55..f310d9438dff 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1283,6 +1283,33 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
> mci_writel(host, CTYPE, (slot->ctype << slot->id));
> }
>
> +static void dw_mci_set_data_timeout(struct dw_mci *host,
> + unsigned int timeout_ns)
> +{
> + u32 clk_div, tmout;
> + u64 tmp;
> +
> + clk_div = (mci_readl(host, CLKDIV) & 0xFF) * 2;
> + if (clk_div == 0)
> + clk_div = 1;
> +
> + tmp = DIV_ROUND_UP_ULL((u64)timeout_ns * host->bus_hz, NSEC_PER_SEC);
> + tmp = DIV_ROUND_UP_ULL(tmp, clk_div);
> +
> + /* TMOUT[7:0] (RESPONSE_TIMEOUT) */
> + tmout = 0xFF; /* Set maximum */
> +
> + /* TMOUT[31:8] (DATA_TIMEOUT) */
> + if (!tmp || tmp > 0xFFFFFF)
> + tmout |= (0xFFFFFF << 8);
> + else
> + tmout |= (tmp & 0xFFFFFF) << 8;
> +
> + mci_writel(host, TMOUT, tmout);
> + dev_dbg(host->dev, "timeout_ns: %u => TMOUT[31:8]: 0x%#08x",
> + timeout_ns, tmout >> 8);
> +}
> +
> static void __dw_mci_start_request(struct dw_mci *host,
> struct dw_mci_slot *slot,
> struct mmc_command *cmd)
> @@ -1303,7 +1330,7 @@ static void __dw_mci_start_request(struct dw_mci *host,
>
> data = cmd->data;
> if (data) {
> - mci_writel(host, TMOUT, 0xFFFFFFFF);
> + dw_mci_set_data_timeout(host, data->timeout_ns);
> mci_writel(host, BYTCNT, data->blksz*data->blocks);
> mci_writel(host, BLKSIZ, data->blksz);
> }
>
