From b3e1ea16fb39fb6e1a1cf1dbdd6738531de3dc7d Mon Sep 17 00:00:00 2001
From: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Date: Thu, 15 Oct 2020 17:41:15 +0800
Subject: [PATCH 1/3] mmc: sdhci: Use Auto CMD Auto Select only when v4_mode is
true
sdhci-of-dwcmshc meets an eMMC read performance regression with below
command after commit 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto
Select support"):
dd if=/dev/mmcblk0 of=/dev/null bs=8192 count=100000
Before the commit, the above command gives 120MB/s
After the commit, the above command gives 51.3 MB/s
So it looks like sdhci-of-dwcmshc expects Version 4 Mode for Auto
CMD Auto Select. Fix the performance degradation by ensuring v4_mode
is true to use Auto CMD Auto Select.
Fixes: 427b6514d095 ("mmc: sdhci: Add Auto CMD Auto Select support")
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201015174115.4cf2c19a@xhacker.debian
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/mmc/host/sdhci.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 592a55a34b58..3561ae8a481a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1384,9 +1384,11 @@ static inline void sdhci_auto_cmd_select(struct sdhci_host *host,
/*
* In case of Version 4.10 or later, use of 'Auto CMD Auto
* Select' is recommended rather than use of 'Auto CMD12
- * Enable' or 'Auto CMD23 Enable'.
+ * Enable' or 'Auto CMD23 Enable'. We require Version 4 Mode
+ * here because some controllers (e.g sdhci-of-dwmshc) expect it.
*/
- if (host->version >= SDHCI_SPEC_410 && (use_cmd12 || use_cmd23)) {
+ if (host->version >= SDHCI_SPEC_410 && host->v4_mode &&
+ (use_cmd12 || use_cmd23)) {
*mode |= SDHCI_TRNS_AUTO_SEL;
ctrl2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
From 0add6e9b88d0632a25323aaf4987dbacb0e4ae64 Mon Sep 17 00:00:00 2001
From: Michael Walle <michael@walle.cc>
Date: Fri, 23 Oct 2020 00:23:37 +0200
Subject: [PATCH 2/3] mmc: sdhci-of-esdhc: set timeout to max before tuning
On rare occations there is the following error:
mmc0: Tuning timeout, falling back to fixed sampling clock
There are SD cards which takes a significant longer time to reply to the
first CMD19 command. The eSDHC takes the data timeout value into account
during the tuning period. The SDHCI core doesn't explicitly set this
timeout for the tuning procedure. Thus on the slow cards, there might be
a spurious "Buffer Read Ready" interrupt, which in turn triggers a wrong
sequence of events. In the end this will lead to an unsuccessful tuning
procedure and to the above error.
To workaround this, set the timeout to the maximum value (which is the
best we can do) and the SDHCI core will take care of the proper timeout
handling.
Fixes: ba49cbd0936e ("mmc: sdhci-of-esdhc: add tuning support")
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201022222337.19857-1-michael@walle.cc
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/mmc/host/sdhci-of-esdhc.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 0b45eff6fed4..baf7801a1804 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -1052,6 +1052,17 @@ static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
esdhc_tuning_block_enable(host, true);
+ /*
+ * The eSDHC controller takes the data timeout value into account
+ * during tuning. If the SD card is too slow sending the response, the
+ * timer will expire and a "Buffer Read Ready" interrupt without data
+ * is triggered. This leads to tuning errors.
+ *
+ * Just set the timeout to the maximum value because the core will
+ * already take care of it in sdhci_send_tuning().
+ */
+ sdhci_writeb(host, 0xe, SDHCI_TIMEOUT_CONTROL);
+
hs400_tuning = host->flags & SDHCI_HS400_TUNING;
do {
From 011fde48394b7dc8dfd6660d1013b26a00157b80 Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Tue, 20 Oct 2020 16:11:16 +0800
Subject: [PATCH 3/3] mmc: sdhci-of-esdhc: make sure delay chain locked for
HS400
For eMMC HS400 mode initialization, the DLL reset is a required step
if DLL is enabled to use previously, like in bootloader.
This step has not been documented in reference manual, but the RM will
be fixed sooner or later.
This patch is to add the step of DLL reset, and make sure delay chain
locked for HS400.
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20201020081116.20918-1-yangbo.lu@nxp.com
Fixes: 54e08d9a95ca ("mmc: sdhci-of-esdhc: add hs400 mode support")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/mmc/host/sdhci-esdhc.h | 2 ++
drivers/mmc/host/sdhci-of-esdhc.c | 17 +++++++++++++++++
2 files changed, 19 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index a30796e79b1c..6de02f09c322 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -5,6 +5,7 @@
* Copyright (c) 2007 Freescale Semiconductor, Inc.
* Copyright (c) 2009 MontaVista Software, Inc.
* Copyright (c) 2010 Pengutronix e.K.
+ * Copyright 2020 NXP
* Author: Wolfram Sang <kernel@pengutronix.de>
*/
@@ -88,6 +89,7 @@
/* DLL Config 0 Register */
#define ESDHC_DLLCFG0 0x160
#define ESDHC_DLL_ENABLE 0x80000000
+#define ESDHC_DLL_RESET 0x40000000
#define ESDHC_DLL_FREQ_SEL 0x08000000
/* DLL Config 1 Register */
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index baf7801a1804..bb094459196a 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -4,6 +4,7 @@
*
* Copyright (c) 2007, 2010, 2012 Freescale Semiconductor, Inc.
* Copyright (c) 2009 MontaVista Software, Inc.
+ * Copyright 2020 NXP
*
* Authors: Xiaobo Xie <X.Xie@freescale.com>
* Anton Vorontsov <avorontsov@ru.mvista.com>
@@ -19,6 +20,7 @@
#include <linux/clk.h>
#include <linux/ktime.h>
#include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include "sdhci-pltfm.h"
@@ -743,6 +745,21 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
if (host->mmc->actual_clock == MMC_HS200_MAX_DTR)
temp |= ESDHC_DLL_FREQ_SEL;
sdhci_writel(host, temp, ESDHC_DLLCFG0);
+
+ temp |= ESDHC_DLL_RESET;
+ sdhci_writel(host, temp, ESDHC_DLLCFG0);
+ udelay(1);
+ temp &= ~ESDHC_DLL_RESET;
+ sdhci_writel(host, temp, ESDHC_DLLCFG0);
+
+ /* Wait max 20 ms */
+ if (read_poll_timeout(sdhci_readl, temp,
+ temp & ESDHC_DLL_STS_SLV_LOCK,
+ 10, 20000, false,
+ host, ESDHC_DLLSTAT0))
+ pr_err("%s: timeout for delay chain lock.\n",
+ mmc_hostname(host->mmc));
+
temp = sdhci_readl(host, ESDHC_TBCTL);
sdhci_writel(host, temp | ESDHC_HS400_WNDW_ADJUST, ESDHC_TBCTL);