Thread (5 messages) 5 messages, 2 authors, 2017-10-04
STALE3216d

[PATCH 2/3] mmc: meson-gx: fix rx phase reset

From: jbrunet@baylibre.com (Jerome Brunet)
Date: 2017-10-02 12:27:58
Also in: linux-amlogic, linux-mmc, lkml
Subsystem: arm/amlogic meson soc support, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers: Neil Armstrong, Kevin Hilman, Ulf Hansson, Linus Torvalds

Resetting the phase when POWER_ON is set the set_ios() call means that the
phase is reset almost every time the set_ios() is called, while the
expected behavior was to reset the phase on a power cycle.

This had gone unnoticed until now because in all mode (except hs400) the
tuning is done after the last to set_ios(). In such case, the tuning
result is used anyway.  In HS400, there are a few calls to set_ios() after
the tuning is done, overwriting the tuning result.

Resetting the phase on POWER_UP instead of POWER_ON solve the problem.

Fixes: d341ca88eead ("mmc: meson-gx: rework tuning function")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 421c8719c202..08a55c2e96e1 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -745,6 +745,10 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	case MMC_POWER_UP:
 		if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
+
+		/* Reset rx phase */
+		clk_set_phase(host->rx_clk, 0);
+
 		break;
 
 	case MMC_POWER_ON:
@@ -758,8 +762,6 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				host->vqmmc_enabled = true;
 		}
 
-		/* Reset rx phase */
-		clk_set_phase(host->rx_clk, 0);
 		break;
 	}
 
-- 
2.13.5
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