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SubjectRe: [PATCH] Revert "mmc: meson-gx: include tx phase in the tuning process"
On 12 February 2018 at 14:13, Jerome Brunet <jbrunet@baylibre.com> wrote:
> This reverts commit 0a44697627d17a66d7dc98f17aeca07ca79c5c20.
>
> This commit was initially intended to fix problems with hs200 and hs400
> on some boards, mainly the odroid-c2. The OC2 (Rev 0.2) I have performs
> well in this modes, so I could not confirm these issues.
>
> We've had several reports about the issues being still present on (some)
> OC2, so apparently, this change does not do what it was supposed to do.
> Maybe the eMMC signal quality is on the edge on the board. This may
> explain the variability we see in term of stability, but this is just a
> guess. Lowering the max_frequency to 100Mhz seems to do trick for those
> affected by the issue
>
> Worse, the commit created new issues (CRC errors and hangs) on other
> boards, such as the kvim 1 and 2, the p200 or the libretech-cc.
>
> According to amlogic, the Tx phase should not be tuned and left in its
> default configuration, so it is best to just revert the commit.
>
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Thanks, applied for fixes and added a stable/fixes tag.

Kind regards
Uffe

> ---
> drivers/mmc/host/meson-gx-mmc.c | 19 +------------------
> 1 file changed, 1 insertion(+), 18 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 22438ebfe4e6..4f972b879fe6 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -717,22 +717,6 @@ static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
> static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> {
> struct meson_host *host = mmc_priv(mmc);
> - int ret;
> -
> - /*
> - * If this is the initial tuning, try to get a sane Rx starting
> - * phase before doing the actual tuning.
> - */
> - if (!mmc->doing_retune) {
> - ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
> -
> - if (ret)
> - return ret;
> - }
> -
> - ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->tx_clk);
> - if (ret)
> - return ret;
>
> return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
> }
> @@ -763,9 +747,8 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> if (!IS_ERR(mmc->supply.vmmc))
> mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
>
> - /* Reset phases */
> + /* Reset rx phase */
> clk_set_phase(host->rx_clk, 0);
> - clk_set_phase(host->tx_clk, 270);
>
> break;
>
> --
> 2.14.3
>

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