[PATCH] mmc: sdhci-of-dwcmshc: Promote the th1520 reset handling to ip level

[PATCH] mmc: sdhci-of-dwcmshc: Promote the th1520 reset handling to ip level

[Jisheng Zhang]

Commit 27e8fe0da3b7 ("mmc: sdhci-of-dwcmshc: Prevent stale command
interrupt handling") clears pending interrupts when resetting
host->pending_reset to ensure no pending stale interrupts after
sdhci_threaded_irq restores interrupts. But this fix is only added for
th1520 platforms, in fact per my test, this issue exists on all
dwcmshc users, such as cv1800b, sg2002, and synaptics platforms.

So promote the above reset handling from th1520 to ip level.

Fixes: 017199c2849c ("mmc: sdhci-of-dwcmshc: Add support for Sophgo CV1800B and SG2002")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 drivers/mmc/host/sdhci-of-dwcmshc.c | 35 ++++++++++++++++-------------
 1 file changed, 20 insertions(+), 15 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index eebd45389956..c17168edc9fd 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -289,6 +289,19 @@ static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
 	sdhci_adma_write_desc(host, desc, addr, len, cmd);
 }
 
+static void dwcmshc_reset(struct sdhci_host *host, u8 mask)
+{
+	sdhci_reset(host, mask);
+
+	/* The dwcmshc does not comply with the SDHCI specification
+	 * regarding the "Software Reset for CMD line should clear 'Command
+	 * Complete' in the Normal Interrupt Status Register." Clear the bit
+	 * here to compensate for this quirk.
+	 */
+	if (mask & SDHCI_RESET_CMD)
+		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
+}
+
 static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -686,7 +699,7 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
 		reset_control_deassert(priv->reset);
 	}
 
-	sdhci_reset(host, mask);
+	dwcmshc_reset(host, mask);
 }
 
 static int dwcmshc_rk35xx_init(struct device *dev, struct sdhci_host *host,
@@ -832,15 +845,7 @@ static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
 	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
 	u16 ctrl_2;
 
-	sdhci_reset(host, mask);
-
-	/* The T-Head 1520 SoC does not comply with the SDHCI specification
-	 * regarding the "Software Reset for CMD line should clear 'Command
-	 * Complete' in the Normal Interrupt Status Register." Clear the bit
-	 * here to compensate for this quirk.
-	 */
-	if (mask & SDHCI_RESET_CMD)
-		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
+	dwcmshc_reset(host, mask);
 
 	if (priv->flags & FLAG_IO_FIXED_1V8) {
 		ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
@@ -886,7 +891,7 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
 	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
 	u32 val, emmc_caps = MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
 
-	sdhci_reset(host, mask);
+	dwcmshc_reset(host, mask);
 
 	if ((host->mmc->caps2 & emmc_caps) == emmc_caps) {
 		val = sdhci_readl(host, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
@@ -958,7 +963,7 @@ static void cv18xx_sdhci_post_tuning(struct sdhci_host *host)
 	val |= SDHCI_INT_DATA_AVAIL;
 	sdhci_writel(host, val, SDHCI_INT_STATUS);
 
-	sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+	dwcmshc_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
 }
 
 static int cv18xx_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
@@ -1080,7 +1085,7 @@ static inline void sg2042_sdhci_phy_init(struct sdhci_host *host)
 
 static void sg2042_sdhci_reset(struct sdhci_host *host, u8 mask)
 {
-	sdhci_reset(host, mask);
+	dwcmshc_reset(host, mask);
 
 	if (mask & SDHCI_RESET_ALL)
 		sg2042_sdhci_phy_init(host);
@@ -1100,7 +1105,7 @@ static const struct sdhci_ops sdhci_dwcmshc_ops = {
 	.set_bus_width		= sdhci_set_bus_width,
 	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
 	.get_max_clock		= dwcmshc_get_max_clock,
-	.reset			= sdhci_reset,
+	.reset			= dwcmshc_reset,
 	.adma_write_desc	= dwcmshc_adma_write_desc,
 	.irq			= dwcmshc_cqe_irq_handler,
 };
@@ -1121,7 +1126,7 @@ static const struct sdhci_ops sdhci_dwcmshc_bf3_ops = {
 	.set_bus_width		= sdhci_set_bus_width,
 	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
 	.get_max_clock		= dwcmshc_get_max_clock,
-	.reset			= sdhci_reset,
+	.reset			= dwcmshc_reset,
 	.adma_write_desc	= dwcmshc_adma_write_desc,
 	.irq			= dwcmshc_cqe_irq_handler,
 	.hw_reset		= dwcmshc_bf3_hw_reset,
-- 
2.50.0

Re: [PATCH] mmc: sdhci-of-dwcmshc: Promote the th1520 reset handling to ip level

[Shawn Lin]

Hi Jisheng,

在 2025/11/12 星期三 8:14, Jisheng Zhang 写道:
> Commit 27e8fe0da3b7 ("mmc: sdhci-of-dwcmshc: Prevent stale command
> interrupt handling") clears pending interrupts when resetting
> host->pending_reset to ensure no pending stale interrupts after
> sdhci_threaded_irq restores interrupts. But this fix is only added for
> th1520 platforms, in fact per my test, this issue exists on all
> dwcmshc users, such as cv1800b, sg2002, and synaptics platforms.
> 
> So promote the above reset handling from th1520 to ip level.
 > > Fixes: 017199c2849c ("mmc: sdhci-of-dwcmshc: Add support for Sophgo 
CV1800B and SG2002")
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
>   drivers/mmc/host/sdhci-of-dwcmshc.c | 35 ++++++++++++++++-------------
>   1 file changed, 20 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index eebd45389956..c17168edc9fd 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -289,6 +289,19 @@ static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
>   	sdhci_adma_write_desc(host, desc, addr, len, cmd);
>   }
>   
> +static void dwcmshc_reset(struct sdhci_host *host, u8 mask)
> +{
> +	sdhci_reset(host, mask);
> +
> +	/* The dwcmshc does not comply with the SDHCI specification
> +	 * regarding the "Software Reset for CMD line should clear 'Command
> +	 * Complete' in the Normal Interrupt Status Register." Clear the bit
> +	 * here to compensate for this quirk.
> +	 */
> +	if (mask & SDHCI_RESET_CMD)
> +		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
> +}
> +
>   static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
>   {
>   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -686,7 +699,7 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
>   		reset_control_deassert(priv->reset);
>   	}
>   
> -	sdhci_reset(host, mask);
> +	dwcmshc_reset(host, mask);

Thanks for the patch. However, I'm afraid it's overkill for the IP used
by Rockchip at least. From the databook v1.70a released by synopsys, it
clearly says:

"The following registers and bits are cleared by this bit:
- Present State register - Command Inhibit (CMD) bit
- Normal Interrupt Status register - Command Complete bit
- Error Interrupt Status - Response error statuses related
to Command Inhibit (CMD) bit "

To be more rigorous, I askeed my IC team performed a simulation this
morning. The results confirmed that the IP's behavior complies with the 
description in the databook.

Is this a problem with an early version of the dwc IP? If so, I think it
should cc all users of this driver to have a check if making it a IP
level change.

>   }
>   
>   static int dwcmshc_rk35xx_init(struct device *dev, struct sdhci_host *host,
> @@ -832,15 +845,7 @@ static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
>   	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
>   	u16 ctrl_2;
>   
> -	sdhci_reset(host, mask);
> -
> -	/* The T-Head 1520 SoC does not comply with the SDHCI specification
> -	 * regarding the "Software Reset for CMD line should clear 'Command
> -	 * Complete' in the Normal Interrupt Status Register." Clear the bit
> -	 * here to compensate for this quirk.
> -	 */
> -	if (mask & SDHCI_RESET_CMD)
> -		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
> +	dwcmshc_reset(host, mask);
>   
>   	if (priv->flags & FLAG_IO_FIXED_1V8) {
>   		ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> @@ -886,7 +891,7 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
>   	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
>   	u32 val, emmc_caps = MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
>   
> -	sdhci_reset(host, mask);
> +	dwcmshc_reset(host, mask);
>   
>   	if ((host->mmc->caps2 & emmc_caps) == emmc_caps) {
>   		val = sdhci_readl(host, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
> @@ -958,7 +963,7 @@ static void cv18xx_sdhci_post_tuning(struct sdhci_host *host)
>   	val |= SDHCI_INT_DATA_AVAIL;
>   	sdhci_writel(host, val, SDHCI_INT_STATUS);
>   
> -	sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> +	dwcmshc_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
>   }
>   
>   static int cv18xx_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
> @@ -1080,7 +1085,7 @@ static inline void sg2042_sdhci_phy_init(struct sdhci_host *host)
>   
>   static void sg2042_sdhci_reset(struct sdhci_host *host, u8 mask)
>   {
> -	sdhci_reset(host, mask);
> +	dwcmshc_reset(host, mask);
>   
>   	if (mask & SDHCI_RESET_ALL)
>   		sg2042_sdhci_phy_init(host);
> @@ -1100,7 +1105,7 @@ static const struct sdhci_ops sdhci_dwcmshc_ops = {
>   	.set_bus_width		= sdhci_set_bus_width,
>   	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
>   	.get_max_clock		= dwcmshc_get_max_clock,
> -	.reset			= sdhci_reset,
> +	.reset			= dwcmshc_reset,
>   	.adma_write_desc	= dwcmshc_adma_write_desc,
>   	.irq			= dwcmshc_cqe_irq_handler,
>   };
> @@ -1121,7 +1126,7 @@ static const struct sdhci_ops sdhci_dwcmshc_bf3_ops = {
>   	.set_bus_width		= sdhci_set_bus_width,
>   	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
>   	.get_max_clock		= dwcmshc_get_max_clock,
> -	.reset			= sdhci_reset,
> +	.reset			= dwcmshc_reset,
>   	.adma_write_desc	= dwcmshc_adma_write_desc,
>   	.irq			= dwcmshc_cqe_irq_handler,
>   	.hw_reset		= dwcmshc_bf3_hw_reset,

Re: [PATCH] mmc: sdhci-of-dwcmshc: Promote the th1520 reset handling to ip level

[Jisheng Zhang]

On Wed, Nov 12, 2025 at 03:01:43PM +0800, Shawn Lin wrote:
> Hi Jisheng,

Hi

> 
> 在 2025/11/12 星期三 8:14, Jisheng Zhang 写道:
> > Commit 27e8fe0da3b7 ("mmc: sdhci-of-dwcmshc: Prevent stale command
> > interrupt handling") clears pending interrupts when resetting
> > host->pending_reset to ensure no pending stale interrupts after
> > sdhci_threaded_irq restores interrupts. But this fix is only added for
> > th1520 platforms, in fact per my test, this issue exists on all
> > dwcmshc users, such as cv1800b, sg2002, and synaptics platforms.
> > 
> > So promote the above reset handling from th1520 to ip level.
> > > Fixes: 017199c2849c ("mmc: sdhci-of-dwcmshc: Add support for Sophgo
> CV1800B and SG2002")
> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> > ---
> >   drivers/mmc/host/sdhci-of-dwcmshc.c | 35 ++++++++++++++++-------------
> >   1 file changed, 20 insertions(+), 15 deletions(-)
> > 
> > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > index eebd45389956..c17168edc9fd 100644
> > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > @@ -289,6 +289,19 @@ static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
> >   	sdhci_adma_write_desc(host, desc, addr, len, cmd);
> >   }
> > +static void dwcmshc_reset(struct sdhci_host *host, u8 mask)
> > +{
> > +	sdhci_reset(host, mask);
> > +
> > +	/* The dwcmshc does not comply with the SDHCI specification
> > +	 * regarding the "Software Reset for CMD line should clear 'Command
> > +	 * Complete' in the Normal Interrupt Status Register." Clear the bit
> > +	 * here to compensate for this quirk.
> > +	 */
> > +	if (mask & SDHCI_RESET_CMD)
> > +		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
> > +}
> > +
> >   static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
> >   {
> >   	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> > @@ -686,7 +699,7 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> >   		reset_control_deassert(priv->reset);
> >   	}
> > -	sdhci_reset(host, mask);
> > +	dwcmshc_reset(host, mask);
> 
> Thanks for the patch. However, I'm afraid it's overkill for the IP used
> by Rockchip at least. From the databook v1.70a released by synopsys, it
> clearly says:
> 
> "The following registers and bits are cleared by this bit:
> - Present State register - Command Inhibit (CMD) bit
> - Normal Interrupt Status register - Command Complete bit
> - Error Interrupt Status - Response error statuses related
> to Command Inhibit (CMD) bit "

The fact seems different. I have both 1.70a and 1.80a platforms, and
the issue exists on both plaforms.

> 
> To be more rigorous, I askeed my IC team performed a simulation this
> morning. The results confirmed that the IP's behavior complies with the
> description in the databook.

See above. NOTE: this isn't 100% reproduced. And per my testing, doesn't
exists with EMMC case. It's easier to be reproduced when using the host
for sdio card, e.g sdio wifi.

> 
> Is this a problem with an early version of the dwc IP? If so, I think it

See above, this exists on 1.80a too. And I belive the ip version on th1520,
cv1800b and sg2002 is not earlier than 1.70a. 

From another side, clearing SDHCI_INT_RESPONSE does no harm.

> should cc all users of this driver to have a check if making it a IP
> level change.
> 
> >   }
> >   static int dwcmshc_rk35xx_init(struct device *dev, struct sdhci_host *host,
> > @@ -832,15 +845,7 @@ static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
> >   	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> >   	u16 ctrl_2;
> > -	sdhci_reset(host, mask);
> > -
> > -	/* The T-Head 1520 SoC does not comply with the SDHCI specification
> > -	 * regarding the "Software Reset for CMD line should clear 'Command
> > -	 * Complete' in the Normal Interrupt Status Register." Clear the bit
> > -	 * here to compensate for this quirk.
> > -	 */
> > -	if (mask & SDHCI_RESET_CMD)
> > -		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
> > +	dwcmshc_reset(host, mask);
> >   	if (priv->flags & FLAG_IO_FIXED_1V8) {
> >   		ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > @@ -886,7 +891,7 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
> >   	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
> >   	u32 val, emmc_caps = MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
> > -	sdhci_reset(host, mask);
> > +	dwcmshc_reset(host, mask);
> >   	if ((host->mmc->caps2 & emmc_caps) == emmc_caps) {
> >   		val = sdhci_readl(host, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
> > @@ -958,7 +963,7 @@ static void cv18xx_sdhci_post_tuning(struct sdhci_host *host)
> >   	val |= SDHCI_INT_DATA_AVAIL;
> >   	sdhci_writel(host, val, SDHCI_INT_STATUS);
> > -	sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> > +	dwcmshc_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> >   }
> >   static int cv18xx_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
> > @@ -1080,7 +1085,7 @@ static inline void sg2042_sdhci_phy_init(struct sdhci_host *host)
> >   static void sg2042_sdhci_reset(struct sdhci_host *host, u8 mask)
> >   {
> > -	sdhci_reset(host, mask);
> > +	dwcmshc_reset(host, mask);
> >   	if (mask & SDHCI_RESET_ALL)
> >   		sg2042_sdhci_phy_init(host);
> > @@ -1100,7 +1105,7 @@ static const struct sdhci_ops sdhci_dwcmshc_ops = {
> >   	.set_bus_width		= sdhci_set_bus_width,
> >   	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
> >   	.get_max_clock		= dwcmshc_get_max_clock,
> > -	.reset			= sdhci_reset,
> > +	.reset			= dwcmshc_reset,
> >   	.adma_write_desc	= dwcmshc_adma_write_desc,
> >   	.irq			= dwcmshc_cqe_irq_handler,
> >   };
> > @@ -1121,7 +1126,7 @@ static const struct sdhci_ops sdhci_dwcmshc_bf3_ops = {
> >   	.set_bus_width		= sdhci_set_bus_width,
> >   	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
> >   	.get_max_clock		= dwcmshc_get_max_clock,
> > -	.reset			= sdhci_reset,
> > +	.reset			= dwcmshc_reset,
> >   	.adma_write_desc	= dwcmshc_adma_write_desc,
> >   	.irq			= dwcmshc_cqe_irq_handler,
> >   	.hw_reset		= dwcmshc_bf3_hw_reset,
> 

Re: [PATCH] mmc: sdhci-of-dwcmshc: Promote the th1520 reset handling to ip level

[Shawn Lin]

在 2025/11/12 星期三 21:11, Jisheng Zhang 写道:
> On Wed, Nov 12, 2025 at 03:01:43PM +0800, Shawn Lin wrote:
>> Hi Jisheng,
> 
> Hi
> 
>>
>> 在 2025/11/12 星期三 8:14, Jisheng Zhang 写道:
>>> Commit 27e8fe0da3b7 ("mmc: sdhci-of-dwcmshc: Prevent stale command
>>> interrupt handling") clears pending interrupts when resetting
>>> host->pending_reset to ensure no pending stale interrupts after
>>> sdhci_threaded_irq restores interrupts. But this fix is only added for
>>> th1520 platforms, in fact per my test, this issue exists on all
>>> dwcmshc users, such as cv1800b, sg2002, and synaptics platforms.
>>>
>>> So promote the above reset handling from th1520 to ip level.
>>>> Fixes: 017199c2849c ("mmc: sdhci-of-dwcmshc: Add support for Sophgo
>> CV1800B and SG2002")
>>> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
>>> ---
>>>    drivers/mmc/host/sdhci-of-dwcmshc.c | 35 ++++++++++++++++-------------
>>>    1 file changed, 20 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
>>> index eebd45389956..c17168edc9fd 100644
>>> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
>>> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
>>> @@ -289,6 +289,19 @@ static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
>>>    	sdhci_adma_write_desc(host, desc, addr, len, cmd);
>>>    }
>>> +static void dwcmshc_reset(struct sdhci_host *host, u8 mask)
>>> +{
>>> +	sdhci_reset(host, mask);
>>> +
>>> +	/* The dwcmshc does not comply with the SDHCI specification
>>> +	 * regarding the "Software Reset for CMD line should clear 'Command
>>> +	 * Complete' in the Normal Interrupt Status Register." Clear the bit
>>> +	 * here to compensate for this quirk.
>>> +	 */
>>> +	if (mask & SDHCI_RESET_CMD)
>>> +		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
>>> +}
>>> +
>>>    static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
>>>    {
>>>    	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>> @@ -686,7 +699,7 @@ static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
>>>    		reset_control_deassert(priv->reset);
>>>    	}
>>> -	sdhci_reset(host, mask);
>>> +	dwcmshc_reset(host, mask);
>>
>> Thanks for the patch. However, I'm afraid it's overkill for the IP used
>> by Rockchip at least. From the databook v1.70a released by synopsys, it
>> clearly says:
>>
>> "The following registers and bits are cleared by this bit:
>> - Present State register - Command Inhibit (CMD) bit
>> - Normal Interrupt Status register - Command Complete bit
>> - Error Interrupt Status - Response error statuses related
>> to Command Inhibit (CMD) bit "
> 
> The fact seems different. I have both 1.70a and 1.80a platforms, and
> the issue exists on both plaforms.
> 
>>
>> To be more rigorous, I askeed my IC team performed a simulation this
>> morning. The results confirmed that the IP's behavior complies with the
>> description in the databook.
> 
> See above. NOTE: this isn't 100% reproduced. And per my testing, doesn't
> exists with EMMC case. It's easier to be reproduced when using the host
> for sdio card, e.g sdio wifi.

That's interesting...How come the digital logic to clear a register is
different between EMMC and SDIO, regarding to the reset signal of
cmdline, I don't know, THB.

But FYI, dwcmshc on Rockchip platform only supports eMMC because of the
IP configuration, that might explain the fact I didn't see it before, if
your test was correct.

> 
>>
>> Is this a problem with an early version of the dwc IP? If so, I think it
> 
> See above, this exists on 1.80a too. And I belive the ip version on th1520,
> cv1800b and sg2002 is not earlier than 1.70a.

Could you possible request a errata from Synopsys? Otherwise I coudld
try to ask one if possible.

> 
>  From another side, clearing SDHCI_INT_RESPONSE does no harm.

I know it's harmless but still I hesitate to extend it to Rockchip IP 
before I could understand what is going on, but not based on speculation 
and testing.

> 
>> should cc all users of this driver to have a check if making it a IP
>> level change.
>>
>>>    }
>>>    static int dwcmshc_rk35xx_init(struct device *dev, struct sdhci_host *host,
>>> @@ -832,15 +845,7 @@ static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
>>>    	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
>>>    	u16 ctrl_2;
>>> -	sdhci_reset(host, mask);
>>> -
>>> -	/* The T-Head 1520 SoC does not comply with the SDHCI specification
>>> -	 * regarding the "Software Reset for CMD line should clear 'Command
>>> -	 * Complete' in the Normal Interrupt Status Register." Clear the bit
>>> -	 * here to compensate for this quirk.
>>> -	 */
>>> -	if (mask & SDHCI_RESET_CMD)
>>> -		sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
>>> +	dwcmshc_reset(host, mask);
>>>    	if (priv->flags & FLAG_IO_FIXED_1V8) {
>>>    		ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>>> @@ -886,7 +891,7 @@ static void cv18xx_sdhci_reset(struct sdhci_host *host, u8 mask)
>>>    	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
>>>    	u32 val, emmc_caps = MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
>>> -	sdhci_reset(host, mask);
>>> +	dwcmshc_reset(host, mask);
>>>    	if ((host->mmc->caps2 & emmc_caps) == emmc_caps) {
>>>    		val = sdhci_readl(host, priv->vendor_specific_area1 + CV18XX_SDHCI_MSHC_CTRL);
>>> @@ -958,7 +963,7 @@ static void cv18xx_sdhci_post_tuning(struct sdhci_host *host)
>>>    	val |= SDHCI_INT_DATA_AVAIL;
>>>    	sdhci_writel(host, val, SDHCI_INT_STATUS);
>>> -	sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
>>> +	dwcmshc_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
>>>    }
>>>    static int cv18xx_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
>>> @@ -1080,7 +1085,7 @@ static inline void sg2042_sdhci_phy_init(struct sdhci_host *host)
>>>    static void sg2042_sdhci_reset(struct sdhci_host *host, u8 mask)
>>>    {
>>> -	sdhci_reset(host, mask);
>>> +	dwcmshc_reset(host, mask);
>>>    	if (mask & SDHCI_RESET_ALL)
>>>    		sg2042_sdhci_phy_init(host);
>>> @@ -1100,7 +1105,7 @@ static const struct sdhci_ops sdhci_dwcmshc_ops = {
>>>    	.set_bus_width		= sdhci_set_bus_width,
>>>    	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
>>>    	.get_max_clock		= dwcmshc_get_max_clock,
>>> -	.reset			= sdhci_reset,
>>> +	.reset			= dwcmshc_reset,
>>>    	.adma_write_desc	= dwcmshc_adma_write_desc,
>>>    	.irq			= dwcmshc_cqe_irq_handler,
>>>    };
>>> @@ -1121,7 +1126,7 @@ static const struct sdhci_ops sdhci_dwcmshc_bf3_ops = {
>>>    	.set_bus_width		= sdhci_set_bus_width,
>>>    	.set_uhs_signaling	= dwcmshc_set_uhs_signaling,
>>>    	.get_max_clock		= dwcmshc_get_max_clock,
>>> -	.reset			= sdhci_reset,
>>> +	.reset			= dwcmshc_reset,
>>>    	.adma_write_desc	= dwcmshc_adma_write_desc,
>>>    	.irq			= dwcmshc_cqe_irq_handler,
>>>    	.hw_reset		= dwcmshc_bf3_hw_reset,
>>
>