armbian-build/patch/kernel/archive/sunxi-6.6/patches.megous/mmc-add-delay-after-power-class-selection.patch

From efe739bcd4a818dc010446f78ce691960919ee50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Jirman?= <megi@xff.cz>
Date: Fri, 16 Mar 2018 20:31:55 +0100
Subject: mmc: add delay after power class selection

This seems to fix issue with sporadic ETIMEOUT in eMMC cache
initialization on second generation TBS A711 tablet.

Signed-off-by: Ondrej Jirman <megi@xff.cz>
---
 drivers/mmc/core/mmc.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 7e39017e440f..30dd2e08eaa2 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1840,6 +1840,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 	 */
 	mmc_select_powerclass(card);
 
+	msleep(20);
+
 	/*
 	 * Enable HPI feature (if supported)
 	 */
@@ -1858,6 +1860,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
 		}
 	}
 
+	msleep(20);
+
 	/*
 	 * If cache size is higher than 0, this indicates the existence of cache
 	 * and it can be turned on. Note that some eMMCs from Micron has been
-- 
2.35.3