This is a note to let you know that I've just added the patch titled
mmc: sdhci-tegra: Fix switch to HS400ES mode
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mmc-sdhci-tegra-fix-switch-to-hs400es-mode.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4fc7261dbab139d3c64c3b618262504e16cfe7ee Mon Sep 17 00:00:00 2001
From: Prathamesh Shete <pshete@xxxxxxxxxx>
Date: Tue, 14 Dec 2021 17:06:53 +0530
Subject: mmc: sdhci-tegra: Fix switch to HS400ES mode
From: Prathamesh Shete <pshete@xxxxxxxxxx>
commit 4fc7261dbab139d3c64c3b618262504e16cfe7ee upstream.
When CMD13 is sent after switching to HS400ES mode, the bus
is operating at either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR.
To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI
interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host
controller CAR clock and the interface clock are rate matched.
Signed-off-by: Prathamesh Shete <pshete@xxxxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Fixes: dfc9700cef77 ("mmc: tegra: Implement HS400 enhanced strobe")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20211214113653.4631-1-pshete@xxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 43 ++++++++++++++++++++++++-----------------
1 file changed, 26 insertions(+), 17 deletions(-)
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -356,23 +356,6 @@ static void tegra_sdhci_set_tap(struct s
}
}
-static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc,
- struct mmc_ios *ios)
-{
- struct sdhci_host *host = mmc_priv(mmc);
- u32 val;
-
- val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
-
- if (ios->enhanced_strobe)
- val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
- else
- val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
-
- sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
-
-}
-
static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -793,6 +776,32 @@ static void tegra_sdhci_set_clock(struct
}
}
+static void tegra_sdhci_hs400_enhanced_strobe(struct mmc_host *mmc,
+ struct mmc_ios *ios)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ u32 val;
+
+ val = sdhci_readl(host, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
+
+ if (ios->enhanced_strobe) {
+ val |= SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
+ /*
+ * When CMD13 is sent from mmc_select_hs400es() after
+ * switching to HS400ES mode, the bus is operating at
+ * either MMC_HIGH_26_MAX_DTR or MMC_HIGH_52_MAX_DTR.
+ * To meet Tegra SDHCI requirement at HS400ES mode, force SDHCI
+ * interface clock to MMC_HS200_MAX_DTR (200 MHz) so that host
+ * controller CAR clock and the interface clock are rate matched.
+ */
+ tegra_sdhci_set_clock(host, MMC_HS200_MAX_DTR);
+ } else {
+ val &= ~SDHCI_TEGRA_SYS_SW_CTRL_ENHANCED_STROBE;
+ }
+
+ sdhci_writel(host, val, SDHCI_TEGRA_VENDOR_SYS_SW_CTRL);
+}
+
static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
Patches currently in stable-queue which might be from pshete@xxxxxxxxxx are
queue-5.15/mmc-sdhci-tegra-fix-switch-to-hs400es-mode.patch
