+ Anand
On Tue, 10 Oct 2023 at 18:44, Ziyang Huang <hzyitc@xxxxxxxxxxx> wrote:
>
> Commit 4bc31edebde5 ("mmc: core: Set HS clock speed before sending
> HS CMD13") set HS clock (52MHz) before switching to HS mode. For this
> freq, FCLK_DIV5 will be selected and div value is 10 (reg value is 9).
> Then we set rx_clk_phase to 11 or 15 which is out of range and make
> hardware frozen. After we send command request, no irq will be
> interrupted and the mmc driver will keep to wait for request finished,
> even durning rebooting.
>
> So let's set it to Phase 90 which should work in most cases. Then let
> meson_mx_sdhc_execute_tuning() to find the accurate value for data
> transfer.
>
> If this doesn't work, maybe need to define a factor in dts.
>
> Fixes: e4bf1b0970ef ("mmc: host: meson-mx-sdhc: new driver for the Amlogic Meson SDHC host")
> Signed-off-by: Ziyang Huang <hzyitc@xxxxxxxxxxx>
Let's give this a try! Although, rather than queuing it as a fix for
v6.7, I am picking it for v6.8 and adding a stable tag, this should
allow it to become a bit more tested first.
Kind regards
Uffe
> ---
> Changes since v1:
> Use Phase 90 instand of value 1
>
> drivers/mmc/host/meson-mx-sdhc-mmc.c | 26 +++++---------------------
> 1 file changed, 5 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-mx-sdhc-mmc.c b/drivers/mmc/host/meson-mx-sdhc-mmc.c
> index 97168cdfa8e9..29698fceb89c 100644
> --- a/drivers/mmc/host/meson-mx-sdhc-mmc.c
> +++ b/drivers/mmc/host/meson-mx-sdhc-mmc.c
> @@ -269,7 +269,7 @@ static int meson_mx_sdhc_enable_clks(struct mmc_host *mmc)
> static int meson_mx_sdhc_set_clk(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> struct meson_mx_sdhc_host *host = mmc_priv(mmc);
> - u32 rx_clk_phase;
> + u32 val, rx_clk_phase;
> int ret;
>
> meson_mx_sdhc_disable_clks(mmc);
> @@ -290,27 +290,11 @@ static int meson_mx_sdhc_set_clk(struct mmc_host *mmc, struct mmc_ios *ios)
> mmc->actual_clock = clk_get_rate(host->sd_clk);
>
> /*
> - * according to Amlogic the following latching points are
> - * selected with empirical values, there is no (known) formula
> - * to calculate these.
> + * Phase 90 should work in most cases. For data transmission,
> + * meson_mx_sdhc_execute_tuning() will find a accurate value
> */
> - if (mmc->actual_clock > 100000000) {
> - rx_clk_phase = 1;
> - } else if (mmc->actual_clock > 45000000) {
> - if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
> - rx_clk_phase = 15;
> - else
> - rx_clk_phase = 11;
> - } else if (mmc->actual_clock >= 25000000) {
> - rx_clk_phase = 15;
> - } else if (mmc->actual_clock > 5000000) {
> - rx_clk_phase = 23;
> - } else if (mmc->actual_clock > 1000000) {
> - rx_clk_phase = 55;
> - } else {
> - rx_clk_phase = 1061;
> - }
> -
> + regmap_read(host->regmap, MESON_SDHC_CLKC, &val);
> + rx_clk_phase = FIELD_GET(MESON_SDHC_CLKC_CLK_DIV, val) / 4;
> regmap_update_bits(host->regmap, MESON_SDHC_CLK2,
> MESON_SDHC_CLK2_RX_CLK_PHASE,
> FIELD_PREP(MESON_SDHC_CLK2_RX_CLK_PHASE,
> --
> 2.34.1
>
