On Wed, 17 Jul 2019 at 04:39, Ben Chuang <[email protected]> wrote:
>
> The GL9750 and GL9755 chipsets, and possibly others, require PLL Enable
> setup as part of the internal clock setup as described in 3.2.1 Internal
> Clock Setup Sequence of SD Host Controller Simplified Specification
> Version 4.20. This changes the timeouts to the new specification of
> 150ms for each step and is documented as safe for "prior versions which
> do not support PLL Enable."
>
> Signed-off-by: Ben Chuang <[email protected]>
> Co-developed-by: Michael K Johnson <[email protected]>
> Signed-off-by: Michael K Johnson <[email protected]>
> ---
> drivers/mmc/host/sdhci.c | 33 ++++++++++++++++++++++++---------
> 1 file changed, 24 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 59acf8e3331e..fd684d7a5f15 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1636,15 +1636,11 @@ void sdhci_enable_clk(struct sdhci_host *host, u16
> clk)
> clk |= SDHCI_CLOCK_INT_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>
> - /* Wait max 20 ms */
> - timeout = ktime_add_ms(ktime_get(), 20);
> - while (1) {
> - bool timedout = ktime_after(ktime_get(), timeout);
> -
> - clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> - if (clk & SDHCI_CLOCK_INT_STABLE)
> - break;
> - if (timedout) {
> + /* Wait max 150 ms */
> + timeout = ktime_add_ms(ktime_get(), 150);
> + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> + & SDHCI_CLOCK_INT_STABLE)) {
> + if (ktime_after(ktime_get(), timeout)) {
> pr_err("%s: Internal clock never stabilised.\n",
> mmc_hostname(host->mmc));
> sdhci_dumpregs(host);
> @@ -1653,8 +1649,27 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
> udelay(10);
This looks like it could be changed to an usleep_range(), perhaps an
additional change on top?
> }
>
> + clk |= SDHCI_CLOCK_PLL_EN;
> + clk &= ~SDHCI_CLOCK_INT_STABLE;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /* Wait max 150 ms */
> + timeout = ktime_add_ms(ktime_get(), 150);
> + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> + & SDHCI_CLOCK_INT_STABLE)) {
> + if (ktime_after(ktime_get(), timeout)) {
> + pr_err("%s: PLL clock never stabilised.\n",
> + mmc_hostname(host->mmc));
> + sdhci_dumpregs(host);
> + return;
> + }
> + udelay(10);
Ditto.
> + }
> +
> clk |= SDHCI_CLOCK_CARD_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + mdelay(1);
This is new, maybe add a comment and change to usleep_range().
> }
> EXPORT_SYMBOL_GPL(sdhci_enable_clk);
>
> --
> 2.22.0
>
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If you want me to apply the patch, you have to drop the above notice.
Kind regards
Uffe
