On Wed, Dec 11, 2013 at 11:56 AM, Shawn Guo [off-list ref] wrote:

On Wed, Dec 11, 2013 at 11:20:59AM +0800, Dong Aisheng wrote:

quoted

No, the max_to is the max timeout counter value, you need to divide it
by the timeout clock
to get the timeout time.
The defined of this API is return the max timeout value in
miliseconds, so you need to
divide the clock by 1000.
None of these handles the detail bout discard_to.

Let me start it over again.  Here is basically what your patch does.

-     mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+     if (host->ops->get_max_timeout)
+             mmc->max_discard_to = host->ops->get_max_timeout(host);

The only thing that does not work for you in the existing code is the
(1 << 27) part, right?

If so, why not just create a platform hook to return the correct thing
for you platform, i.e. (1 << 28)?

        if (host->ops->get_max_timeout)
                mmc->max_discard_to = host->ops->hook_foo(host);

unsigned int esdhc_hook_foo(struct sdhci_host *host)
{
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct pltfm_imx_data *imx_data = pltfm_host->priv;

        return esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
}

Such patch will be ease to be understood and less offensive to the
existing code, no?

The example you give is not correct here.
The max timeout counter returned by esdhc_hook_foo can not be simpled assigned
to max_discard_to which is timeout in miliseconds.

Actually what i did is like the way you said:
-       mmc->max_discard_to = (1 << 27) / host->timeout_clk;
+       if (host->ops->get_max_timeout)
+               mmc->max_discard_to = host->ops->get_max_timeout(host);
+       else
+               mmc->max_discard_to = (1 << 27) / host->timeout_clk;

+unsigned int esdhc_get_max_timeout(struct sdhci_host *host)
+{
+       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+       struct pltfm_imx_data *imx_data = pltfm_host->priv;
+       u32 max_to = esdhc_is_usdhc(imx_data) ? 1 << 28 : 1 << 27;
+
+       return max_to / (esdhc_pltfm_get_max_clock(host) / 1000);
+}

Regards
Dong Aisheng

Shawn