Hi Marten,
On 11/8/21 8:36 PM, 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.
> Since the software dto_timer acts as a backup in cases when this timeout
> is not long enough, it is normally not a problem. 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>
> ---
>
> v2:
> - Calculate new value before checking boundaries
> - Include CLKDIV register to get proper value
>
> drivers/mmc/host/dw_mmc.c | 32 +++++++++++++++++++++++++++++++-
> 1 file changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 6578cc64ae9e..6edd7a231448 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1283,6 +1283,36 @@ 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)
> +{
> + unsigned int clk_div, tmp, tmout;
> +
> + 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 * clk_div);
> +
> + if (!tmp || tmp > 0xFFFFFF) {
> + /* Set maximum */
"Set maximum value about all Timeout"?
> + tmout = 0xFFFFFFFF;
> + goto tmout_done;
> + }
It doesn't need to use "goto". Instead, if-else can be used.
> +
> + /* TMOUT[7:0] (RESPONSE_TIMEOUT) */
> + tmout = 0xFF; /* Set maximum */
To prevent a confusion, how about add "Set a maximum response timeout"
And this line can be removed.
> +
> + /* TMOUT[31:8] (DATA_TIMEOUT) */
> + tmout |= (tmp & 0xFFFFFF) << 8;
tmout = (0xFF | ((tmp & 0xFFFFFF) << 8));
The entire code can be below
if (!tmp || ....)
tmout = 0xFFFFFFFF;
else
tmout = (0xFF | ((tmp & 0xFFFFFF) << 8));
writel(TMOUT, ...)
How about this?
Best Regards,
Jaehoon Chung
> +
> +tmout_done:
> + mci_writel(host, TMOUT, tmout);
> + dev_dbg(host->dev, "timeout_ns: %u => TMOUT[31:8]: 0x%06x",
> + 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 +1333,7 @@ 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);
> }
>
