2022-12-07 05:31:51

by Wenchao Chen

Subject: [PATCH] mmc: sdhci-sprd: Disable CLK_AUTO when the clock is less than 400K

When the clock is less than 400K, some SD cards fail to initialize
because CLK_AUTO is enabled.

Fixes: fb8bd90f83c4 ("mmc: sdhci-sprd: Add Spreadtrum's initial host controller")
Signed-off-by: Wenchao Chen <[email protected]>
---
drivers/mmc/host/sdhci-sprd.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
index bec3f9e3cd3f..525f979e2a97 100644
--- a/drivers/mmc/host/sdhci-sprd.c
+++ b/drivers/mmc/host/sdhci-sprd.c
@@ -228,13 +228,15 @@ static inline void _sdhci_sprd_set_clock(struct sdhci_host *host,
div = ((div & 0x300) >> 2) | ((div & 0xFF) << 8);
sdhci_enable_clk(host, div);

- /* enable auto gate sdhc_enable_auto_gate */
- val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
- mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
- SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
- if (mask != (val & mask)) {
- val |= mask;
- sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
+ /* Enable CLK_AUTO when the clock is greater than 400K. */
+ if (clk > 400000) {
+ val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
+ mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
+ SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
+ if (mask != (val & mask)) {
+ val |= mask;
+ sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
+ }
}
}

--
2.17.1

2022-12-09 09:55:51

by Ulf Hansson

Subject: Re: [PATCH] mmc: sdhci-sprd: Disable CLK_AUTO when the clock is less than 400K

On Wed, 7 Dec 2022 at 06:20, Wenchao Chen <[email protected]> wrote:
>
> When the clock is less than 400K, some SD cards fail to initialize
> because CLK_AUTO is enabled.
>
> Fixes: fb8bd90f83c4 ("mmc: sdhci-sprd: Add Spreadtrum's initial host controller")
> Signed-off-by: Wenchao Chen <[email protected]>

Applied for next, and by adding a stable tag, thanks!

Kind regards
Uffe

> ---
> drivers/mmc/host/sdhci-sprd.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> index bec3f9e3cd3f..525f979e2a97 100644
> --- a/drivers/mmc/host/sdhci-sprd.c
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -228,13 +228,15 @@ static inline void _sdhci_sprd_set_clock(struct sdhci_host *host,
> div = ((div & 0x300) >> 2) | ((div & 0xFF) << 8);
> sdhci_enable_clk(host, div);
>
> - /* enable auto gate sdhc_enable_auto_gate */
> - val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
> - mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
> - SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
> - if (mask != (val & mask)) {
> - val |= mask;
> - sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
> + /* Enable CLK_AUTO when the clock is greater than 400K. */
> + if (clk > 400000) {
> + val = sdhci_readl(host, SDHCI_SPRD_REG_32_BUSY_POSI);
> + mask = SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN |
> + SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN;
> + if (mask != (val & mask)) {
> + val |= mask;
> + sdhci_writel(host, val, SDHCI_SPRD_REG_32_BUSY_POSI);
> + }
> }
> }
>
> --
> 2.17.1
>