2023-09-15 09:51:02

by Victor Shih

[permalink] [raw]
Subject: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

From: Victor Shih <[email protected]>

Sdhci_uhs2_reset() does a UHS-II specific reset operation.

Signed-off-by: Ben Chuang <[email protected]>
Signed-off-by: AKASHI Takahiro <[email protected]>
Signed-off-by: Victor Shih <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
---

Updates in V8:
- Adjust the position of matching brackets.

Updates in V6:
- Remove unnecessary functions and simplify code.

---

drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
drivers/mmc/host/sdhci-uhs2.h | 2 ++
2 files changed, 47 insertions(+)

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index e339821d3504..dfc80a7f1bad 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -10,7 +10,9 @@
* Author: AKASHI Takahiro <[email protected]>
*/

+#include <linux/delay.h>
#include <linux/module.h>
+#include <linux/iopoll.h>

#include "sdhci.h"
#include "sdhci-uhs2.h"
@@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
}
EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);

+/*****************************************************************************\
+ * *
+ * Low level functions *
+ * *
+\*****************************************************************************/
+
+bool sdhci_uhs2_mode(struct sdhci_host *host)
+{
+ return host->mmc->flags & MMC_UHS2_SUPPORT;
+}
+
+/**
+ * sdhci_uhs2_reset - invoke SW reset
+ * @host: SDHCI host
+ * @mask: Control mask
+ *
+ * Invoke SW reset, depending on a bit in @mask and wait for completion.
+ */
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
+{
+ unsigned long timeout;
+ u32 val;
+
+ sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
+
+ if (mask & SDHCI_UHS2_SW_RESET_FULL)
+ host->clock = 0;
+
+ /* Wait max 100 ms */
+ timeout = 100000;
+
+ /* hw clears the bit when it's done */
+ if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
+ timeout, true, host, SDHCI_UHS2_SW_RESET)) {
+ pr_err("%s: %s: Reset 0x%x never completed.\n", __func__,
+ mmc_hostname(host->mmc), (int)mask);
+ pr_err("%s: clean reset bit\n", mmc_hostname(host->mmc));
+ sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
+ return;
+ }
+}
+EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
+
/*****************************************************************************\
* *
* Driver init/exit *
diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
index 2bfe18d29bca..8253d50f7852 100644
--- a/drivers/mmc/host/sdhci-uhs2.h
+++ b/drivers/mmc/host/sdhci-uhs2.h
@@ -177,5 +177,7 @@
struct sdhci_host;

void sdhci_uhs2_dump_regs(struct sdhci_host *host);
+bool sdhci_uhs2_mode(struct sdhci_host *host);
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);

#endif /* __SDHCI_UHS2_H */
--
2.25.1


2023-10-03 10:31:14

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
>
> From: Victor Shih <[email protected]>
>
> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>
> Signed-off-by: Ben Chuang <[email protected]>
> Signed-off-by: AKASHI Takahiro <[email protected]>
> Signed-off-by: Victor Shih <[email protected]>
> Acked-by: Adrian Hunter <[email protected]>
> ---
>
> Updates in V8:
> - Adjust the position of matching brackets.
>
> Updates in V6:
> - Remove unnecessary functions and simplify code.
>
> ---
>
> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> drivers/mmc/host/sdhci-uhs2.h | 2 ++
> 2 files changed, 47 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index e339821d3504..dfc80a7f1bad 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -10,7 +10,9 @@
> * Author: AKASHI Takahiro <[email protected]>
> */
>
> +#include <linux/delay.h>
> #include <linux/module.h>
> +#include <linux/iopoll.h>
>
> #include "sdhci.h"
> #include "sdhci-uhs2.h"
> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> }
> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>
> +/*****************************************************************************\
> + * *
> + * Low level functions *
> + * *
> +\*****************************************************************************/
> +
> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> +{
> + return host->mmc->flags & MMC_UHS2_SUPPORT;

The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
should be using mmc->ios.timings, which already indicates whether we
are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
this.

That said, I think we should drop the sdhci_uhs2_mode() function
altogether and instead use mmc_card_uhs2(), which means we should move
it to include/linux/mmc/host.h, so it becomes available for host
drivers.

> +}
> +
> +/**
> + * sdhci_uhs2_reset - invoke SW reset
> + * @host: SDHCI host
> + * @mask: Control mask
> + *
> + * Invoke SW reset, depending on a bit in @mask and wait for completion.
> + */
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> +{
> + unsigned long timeout;
> + u32 val;
> +
> + sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
> +
> + if (mask & SDHCI_UHS2_SW_RESET_FULL)
> + host->clock = 0;
> +
> + /* Wait max 100 ms */
> + timeout = 100000;

Please convert into using a define and use that directly, below instead.

> +
> + /* hw clears the bit when it's done */
> + if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
> + timeout, true, host, SDHCI_UHS2_SW_RESET)) {
> + pr_err("%s: %s: Reset 0x%x never completed.\n", __func__,
> + mmc_hostname(host->mmc), (int)mask);
> + pr_err("%s: clean reset bit\n", mmc_hostname(host->mmc));

It looks silly to do two pr_err immediately after each other, please
combine them into one.

Moreover, I think we should probably convert into using a pr_warn() instead.

> + sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
> + return;
> + }
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> +
> /*****************************************************************************\
> * *
> * Driver init/exit *
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index 2bfe18d29bca..8253d50f7852 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -177,5 +177,7 @@
> struct sdhci_host;
>
> void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> +bool sdhci_uhs2_mode(struct sdhci_host *host);
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
>
> #endif /* __SDHCI_UHS2_H */
> --
> 2.25.1
>

Kind regards
Uffe

2023-10-03 11:37:43

by Adrian Hunter

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On 3/10/23 13:30, Ulf Hansson wrote:
> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
>>
>> From: Victor Shih <[email protected]>
>>
>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>
>> Signed-off-by: Ben Chuang <[email protected]>
>> Signed-off-by: AKASHI Takahiro <[email protected]>
>> Signed-off-by: Victor Shih <[email protected]>
>> Acked-by: Adrian Hunter <[email protected]>
>> ---
>>
>> Updates in V8:
>> - Adjust the position of matching brackets.
>>
>> Updates in V6:
>> - Remove unnecessary functions and simplify code.
>>
>> ---
>>
>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
>> 2 files changed, 47 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>> index e339821d3504..dfc80a7f1bad 100644
>> --- a/drivers/mmc/host/sdhci-uhs2.c
>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>> @@ -10,7 +10,9 @@
>> * Author: AKASHI Takahiro <[email protected]>
>> */
>>
>> +#include <linux/delay.h>
>> #include <linux/module.h>
>> +#include <linux/iopoll.h>
>>
>> #include "sdhci.h"
>> #include "sdhci-uhs2.h"
>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>> }
>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>
>> +/*****************************************************************************\
>> + * *
>> + * Low level functions *
>> + * *
>> +\*****************************************************************************/
>> +
>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>> +{
>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
>
> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> should be using mmc->ios.timings, which already indicates whether we
> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> this.
>
> That said, I think we should drop the sdhci_uhs2_mode() function
> altogether and instead use mmc_card_uhs2(), which means we should move
> it to include/linux/mmc/host.h, so it becomes available for host
> drivers.
>

UHS2 mode starts at UHS2 initialization and ends either when UHS2
initialization fails, or the card is removed.

So it includes re-initialization and reset when the transfer mode
currently transitions through MMC_TIMING_LEGACY.

So mmc_card_uhs2() won't work correctly for the host callbacks
unless something is done about that.

2023-10-03 12:22:44

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
>
> On 3/10/23 13:30, Ulf Hansson wrote:
> > On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
> >>
> >> From: Victor Shih <[email protected]>
> >>
> >> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>
> >> Signed-off-by: Ben Chuang <[email protected]>
> >> Signed-off-by: AKASHI Takahiro <[email protected]>
> >> Signed-off-by: Victor Shih <[email protected]>
> >> Acked-by: Adrian Hunter <[email protected]>
> >> ---
> >>
> >> Updates in V8:
> >> - Adjust the position of matching brackets.
> >>
> >> Updates in V6:
> >> - Remove unnecessary functions and simplify code.
> >>
> >> ---
> >>
> >> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >> drivers/mmc/host/sdhci-uhs2.h | 2 ++
> >> 2 files changed, 47 insertions(+)
> >>
> >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >> index e339821d3504..dfc80a7f1bad 100644
> >> --- a/drivers/mmc/host/sdhci-uhs2.c
> >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >> @@ -10,7 +10,9 @@
> >> * Author: AKASHI Takahiro <[email protected]>
> >> */
> >>
> >> +#include <linux/delay.h>
> >> #include <linux/module.h>
> >> +#include <linux/iopoll.h>
> >>
> >> #include "sdhci.h"
> >> #include "sdhci-uhs2.h"
> >> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >> }
> >> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>
> >> +/*****************************************************************************\
> >> + * *
> >> + * Low level functions *
> >> + * *
> >> +\*****************************************************************************/
> >> +
> >> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >> +{
> >> + return host->mmc->flags & MMC_UHS2_SUPPORT;
> >
> > The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> > should be using mmc->ios.timings, which already indicates whether we
> > are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> > this.
> >
> > That said, I think we should drop the sdhci_uhs2_mode() function
> > altogether and instead use mmc_card_uhs2(), which means we should move
> > it to include/linux/mmc/host.h, so it becomes available for host
> > drivers.
> >
>
> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> initialization fails, or the card is removed.
>
> So it includes re-initialization and reset when the transfer mode
> currently transitions through MMC_TIMING_LEGACY.
>
> So mmc_card_uhs2() won't work correctly for the host callbacks
> unless something is done about that.

Right, thanks for clarifying!

In that case I wonder if we couldn't change the way we update the
->ios.timing for UHS2. It seems silly to have two (similar) ways to
indicate that we have moved to UHS2.

Kind regards
Uffe

2023-10-03 15:03:34

by Adrian Hunter

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On 3/10/23 15:22, Ulf Hansson wrote:
> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
>>
>> On 3/10/23 13:30, Ulf Hansson wrote:
>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
>>>>
>>>> From: Victor Shih <[email protected]>
>>>>
>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>>>
>>>> Signed-off-by: Ben Chuang <[email protected]>
>>>> Signed-off-by: AKASHI Takahiro <[email protected]>
>>>> Signed-off-by: Victor Shih <[email protected]>
>>>> Acked-by: Adrian Hunter <[email protected]>
>>>> ---
>>>>
>>>> Updates in V8:
>>>> - Adjust the position of matching brackets.
>>>>
>>>> Updates in V6:
>>>> - Remove unnecessary functions and simplify code.
>>>>
>>>> ---
>>>>
>>>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>>>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
>>>> 2 files changed, 47 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>>>> index e339821d3504..dfc80a7f1bad 100644
>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>>>> @@ -10,7 +10,9 @@
>>>> * Author: AKASHI Takahiro <[email protected]>
>>>> */
>>>>
>>>> +#include <linux/delay.h>
>>>> #include <linux/module.h>
>>>> +#include <linux/iopoll.h>
>>>>
>>>> #include "sdhci.h"
>>>> #include "sdhci-uhs2.h"
>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>>>> }
>>>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>>>
>>>> +/*****************************************************************************\
>>>> + * *
>>>> + * Low level functions *
>>>> + * *
>>>> +\*****************************************************************************/
>>>> +
>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>>>> +{
>>>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
>>>
>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
>>> should be using mmc->ios.timings, which already indicates whether we
>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
>>> this.
>>>
>>> That said, I think we should drop the sdhci_uhs2_mode() function
>>> altogether and instead use mmc_card_uhs2(), which means we should move
>>> it to include/linux/mmc/host.h, so it becomes available for host
>>> drivers.
>>>
>>
>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
>> initialization fails, or the card is removed.
>>
>> So it includes re-initialization and reset when the transfer mode
>> currently transitions through MMC_TIMING_LEGACY.
>>
>> So mmc_card_uhs2() won't work correctly for the host callbacks
>> unless something is done about that.
>
> Right, thanks for clarifying!
>
> In that case I wonder if we couldn't change the way we update the
> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> indicate that we have moved to UHS2.

Perhaps something like below:

diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
index aacefdd6bc9e..e39d63d46041 100644
--- a/drivers/mmc/core/sd_uhs2.c
+++ b/drivers/mmc/core/sd_uhs2.c
@@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)

host->ios.vdd = 0;
host->ios.clock = 0;
- host->ios.timing = MMC_TIMING_LEGACY;
+ /* Must set UHS2 timing to identify UHS2 mode */
+ host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
host->ios.power_mode = MMC_POWER_OFF;
if (host->flags & MMC_UHS2_SD_TRAN)
host->flags &= ~MMC_UHS2_SD_TRAN;
@@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
mmc_claim_host(host);
mmc_detach_bus(host);
sd_uhs2_power_off(host);
- host->flags &= ~MMC_UHS2_SUPPORT;
+ /* Remove UHS2 timing to indicate the end of UHS2 mode */
+ host->ios.timing = MMC_TIMING_LEGACY;
mmc_release_host(host);
}
}
@@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
err:
mmc_detach_bus(host);
sd_uhs2_power_off(host);
- host->flags &= ~MMC_UHS2_SUPPORT;
+ /* Remove UHS2 timing to indicate the end of UHS2 mode */
+ host->ios.timing = MMC_TIMING_LEGACY;
return err;
}

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 517c497112f4..d1f3318b7d3a 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)

/* UHS2 timing. Note, UHS2 timing is disabled when powering off */
ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
- if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
- ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
- ios->timing == MMC_TIMING_UHS2_SPEED_B ||
- ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
+ if (ios->power_mode != MMC_POWER_OFF &&
+ (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
+ ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
+ ios->timing == MMC_TIMING_UHS2_SPEED_B ||
+ ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
else
ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);


2023-10-04 08:36:53

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <[email protected]> wrote:
>
> On 3/10/23 15:22, Ulf Hansson wrote:
> > On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
> >>
> >> On 3/10/23 13:30, Ulf Hansson wrote:
> >>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
> >>>>
> >>>> From: Victor Shih <[email protected]>
> >>>>
> >>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>>>
> >>>> Signed-off-by: Ben Chuang <[email protected]>
> >>>> Signed-off-by: AKASHI Takahiro <[email protected]>
> >>>> Signed-off-by: Victor Shih <[email protected]>
> >>>> Acked-by: Adrian Hunter <[email protected]>
> >>>> ---
> >>>>
> >>>> Updates in V8:
> >>>> - Adjust the position of matching brackets.
> >>>>
> >>>> Updates in V6:
> >>>> - Remove unnecessary functions and simplify code.
> >>>>
> >>>> ---
> >>>>
> >>>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >>>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
> >>>> 2 files changed, 47 insertions(+)
> >>>>
> >>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >>>> index e339821d3504..dfc80a7f1bad 100644
> >>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> >>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >>>> @@ -10,7 +10,9 @@
> >>>> * Author: AKASHI Takahiro <[email protected]>
> >>>> */
> >>>>
> >>>> +#include <linux/delay.h>
> >>>> #include <linux/module.h>
> >>>> +#include <linux/iopoll.h>
> >>>>
> >>>> #include "sdhci.h"
> >>>> #include "sdhci-uhs2.h"
> >>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >>>> }
> >>>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>>>
> >>>> +/*****************************************************************************\
> >>>> + * *
> >>>> + * Low level functions *
> >>>> + * *
> >>>> +\*****************************************************************************/
> >>>> +
> >>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >>>> +{
> >>>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
> >>>
> >>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> >>> should be using mmc->ios.timings, which already indicates whether we
> >>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> >>> this.
> >>>
> >>> That said, I think we should drop the sdhci_uhs2_mode() function
> >>> altogether and instead use mmc_card_uhs2(), which means we should move
> >>> it to include/linux/mmc/host.h, so it becomes available for host
> >>> drivers.
> >>>
> >>
> >> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> >> initialization fails, or the card is removed.
> >>
> >> So it includes re-initialization and reset when the transfer mode
> >> currently transitions through MMC_TIMING_LEGACY.
> >>
> >> So mmc_card_uhs2() won't work correctly for the host callbacks
> >> unless something is done about that.
> >
> > Right, thanks for clarifying!
> >
> > In that case I wonder if we couldn't change the way we update the
> > ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> > indicate that we have moved to UHS2.
>
> Perhaps something like below:
>
> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> index aacefdd6bc9e..e39d63d46041 100644
> --- a/drivers/mmc/core/sd_uhs2.c
> +++ b/drivers/mmc/core/sd_uhs2.c
> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
>
> host->ios.vdd = 0;
> host->ios.clock = 0;
> - host->ios.timing = MMC_TIMING_LEGACY;
> + /* Must set UHS2 timing to identify UHS2 mode */
> + host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
> host->ios.power_mode = MMC_POWER_OFF;
> if (host->flags & MMC_UHS2_SD_TRAN)
> host->flags &= ~MMC_UHS2_SD_TRAN;
> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
> mmc_claim_host(host);
> mmc_detach_bus(host);
> sd_uhs2_power_off(host);
> - host->flags &= ~MMC_UHS2_SUPPORT;
> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> + host->ios.timing = MMC_TIMING_LEGACY;
> mmc_release_host(host);
> }
> }
> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
> err:
> mmc_detach_bus(host);
> sd_uhs2_power_off(host);
> - host->flags &= ~MMC_UHS2_SUPPORT;
> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> + host->ios.timing = MMC_TIMING_LEGACY;
> return err;
> }

I wouldn't mind changing to the above. But, maybe an even better
option is to use the ->timing variable in the struct sdhci_host, as
it's there already to keep track of the current/previous timing state.
Would that work too?

>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 517c497112f4..d1f3318b7d3a 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>
> /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
> ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> - if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> - ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> - ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> - ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> + if (ios->power_mode != MMC_POWER_OFF &&
> + (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> + ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> + ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> + ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
> ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> else
> ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
>
>

Kind regards
Uffe

2023-10-10 10:29:37

by Adrian Hunter

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On 4/10/23 11:35, Ulf Hansson wrote:
> On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <[email protected]> wrote:
>>
>> On 3/10/23 15:22, Ulf Hansson wrote:
>>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
>>>>
>>>> On 3/10/23 13:30, Ulf Hansson wrote:
>>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
>>>>>>
>>>>>> From: Victor Shih <[email protected]>
>>>>>>
>>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>>>>>
>>>>>> Signed-off-by: Ben Chuang <[email protected]>
>>>>>> Signed-off-by: AKASHI Takahiro <[email protected]>
>>>>>> Signed-off-by: Victor Shih <[email protected]>
>>>>>> Acked-by: Adrian Hunter <[email protected]>
>>>>>> ---
>>>>>>
>>>>>> Updates in V8:
>>>>>> - Adjust the position of matching brackets.
>>>>>>
>>>>>> Updates in V6:
>>>>>> - Remove unnecessary functions and simplify code.
>>>>>>
>>>>>> ---
>>>>>>
>>>>>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>>>>>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
>>>>>> 2 files changed, 47 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>>>>>> index e339821d3504..dfc80a7f1bad 100644
>>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
>>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>>>>>> @@ -10,7 +10,9 @@
>>>>>> * Author: AKASHI Takahiro <[email protected]>
>>>>>> */
>>>>>>
>>>>>> +#include <linux/delay.h>
>>>>>> #include <linux/module.h>
>>>>>> +#include <linux/iopoll.h>
>>>>>>
>>>>>> #include "sdhci.h"
>>>>>> #include "sdhci-uhs2.h"
>>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>>>>>> }
>>>>>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>>>>>
>>>>>> +/*****************************************************************************\
>>>>>> + * *
>>>>>> + * Low level functions *
>>>>>> + * *
>>>>>> +\*****************************************************************************/
>>>>>> +
>>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>>>>>> +{
>>>>>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
>>>>>
>>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
>>>>> should be using mmc->ios.timings, which already indicates whether we
>>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
>>>>> this.
>>>>>
>>>>> That said, I think we should drop the sdhci_uhs2_mode() function
>>>>> altogether and instead use mmc_card_uhs2(), which means we should move
>>>>> it to include/linux/mmc/host.h, so it becomes available for host
>>>>> drivers.
>>>>>
>>>>
>>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
>>>> initialization fails, or the card is removed.
>>>>
>>>> So it includes re-initialization and reset when the transfer mode
>>>> currently transitions through MMC_TIMING_LEGACY.
>>>>
>>>> So mmc_card_uhs2() won't work correctly for the host callbacks
>>>> unless something is done about that.
>>>
>>> Right, thanks for clarifying!
>>>
>>> In that case I wonder if we couldn't change the way we update the
>>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
>>> indicate that we have moved to UHS2.
>>
>> Perhaps something like below:
>>
>> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
>> index aacefdd6bc9e..e39d63d46041 100644
>> --- a/drivers/mmc/core/sd_uhs2.c
>> +++ b/drivers/mmc/core/sd_uhs2.c
>> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
>>
>> host->ios.vdd = 0;
>> host->ios.clock = 0;
>> - host->ios.timing = MMC_TIMING_LEGACY;
>> + /* Must set UHS2 timing to identify UHS2 mode */
>> + host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
>> host->ios.power_mode = MMC_POWER_OFF;
>> if (host->flags & MMC_UHS2_SD_TRAN)
>> host->flags &= ~MMC_UHS2_SD_TRAN;
>> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
>> mmc_claim_host(host);
>> mmc_detach_bus(host);
>> sd_uhs2_power_off(host);
>> - host->flags &= ~MMC_UHS2_SUPPORT;
>> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
>> + host->ios.timing = MMC_TIMING_LEGACY;
>> mmc_release_host(host);
>> }
>> }
>> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
>> err:
>> mmc_detach_bus(host);
>> sd_uhs2_power_off(host);
>> - host->flags &= ~MMC_UHS2_SUPPORT;
>> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
>> + host->ios.timing = MMC_TIMING_LEGACY;
>> return err;
>> }
>
> I wouldn't mind changing to the above. But, maybe an even better
> option is to use the ->timing variable in the struct sdhci_host, as
> it's there already to keep track of the current/previous timing state.
> Would that work too?

The host does not really have enough information.

>
>>
>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>> index 517c497112f4..d1f3318b7d3a 100644
>> --- a/drivers/mmc/host/sdhci-uhs2.c
>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>
>> /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
>> ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> - if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
>> - ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
>> - ios->timing == MMC_TIMING_UHS2_SPEED_B ||
>> - ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
>> + if (ios->power_mode != MMC_POWER_OFF &&
>> + (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
>> + ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
>> + ios->timing == MMC_TIMING_UHS2_SPEED_B ||
>> + ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
>> ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
>> else
>> ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
>>
>>
>
> Kind regards
> Uffe

2023-10-10 11:08:55

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On Tue, 10 Oct 2023 at 12:29, Adrian Hunter <[email protected]> wrote:
>
> On 4/10/23 11:35, Ulf Hansson wrote:
> > On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <[email protected]> wrote:
> >>
> >> On 3/10/23 15:22, Ulf Hansson wrote:
> >>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
> >>>>
> >>>> On 3/10/23 13:30, Ulf Hansson wrote:
> >>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
> >>>>>>
> >>>>>> From: Victor Shih <[email protected]>
> >>>>>>
> >>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>>>>>
> >>>>>> Signed-off-by: Ben Chuang <[email protected]>
> >>>>>> Signed-off-by: AKASHI Takahiro <[email protected]>
> >>>>>> Signed-off-by: Victor Shih <[email protected]>
> >>>>>> Acked-by: Adrian Hunter <[email protected]>
> >>>>>> ---
> >>>>>>
> >>>>>> Updates in V8:
> >>>>>> - Adjust the position of matching brackets.
> >>>>>>
> >>>>>> Updates in V6:
> >>>>>> - Remove unnecessary functions and simplify code.
> >>>>>>
> >>>>>> ---
> >>>>>>
> >>>>>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >>>>>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
> >>>>>> 2 files changed, 47 insertions(+)
> >>>>>>
> >>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> index e339821d3504..dfc80a7f1bad 100644
> >>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> @@ -10,7 +10,9 @@
> >>>>>> * Author: AKASHI Takahiro <[email protected]>
> >>>>>> */
> >>>>>>
> >>>>>> +#include <linux/delay.h>
> >>>>>> #include <linux/module.h>
> >>>>>> +#include <linux/iopoll.h>
> >>>>>>
> >>>>>> #include "sdhci.h"
> >>>>>> #include "sdhci-uhs2.h"
> >>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >>>>>> }
> >>>>>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>>>>>
> >>>>>> +/*****************************************************************************\
> >>>>>> + * *
> >>>>>> + * Low level functions *
> >>>>>> + * *
> >>>>>> +\*****************************************************************************/
> >>>>>> +
> >>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >>>>>> +{
> >>>>>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
> >>>>>
> >>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> >>>>> should be using mmc->ios.timings, which already indicates whether we
> >>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> >>>>> this.
> >>>>>
> >>>>> That said, I think we should drop the sdhci_uhs2_mode() function
> >>>>> altogether and instead use mmc_card_uhs2(), which means we should move
> >>>>> it to include/linux/mmc/host.h, so it becomes available for host
> >>>>> drivers.
> >>>>>
> >>>>
> >>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> >>>> initialization fails, or the card is removed.
> >>>>
> >>>> So it includes re-initialization and reset when the transfer mode
> >>>> currently transitions through MMC_TIMING_LEGACY.
> >>>>
> >>>> So mmc_card_uhs2() won't work correctly for the host callbacks
> >>>> unless something is done about that.
> >>>
> >>> Right, thanks for clarifying!
> >>>
> >>> In that case I wonder if we couldn't change the way we update the
> >>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> >>> indicate that we have moved to UHS2.
> >>
> >> Perhaps something like below:
> >>
> >> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> >> index aacefdd6bc9e..e39d63d46041 100644
> >> --- a/drivers/mmc/core/sd_uhs2.c
> >> +++ b/drivers/mmc/core/sd_uhs2.c
> >> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
> >>
> >> host->ios.vdd = 0;
> >> host->ios.clock = 0;
> >> - host->ios.timing = MMC_TIMING_LEGACY;
> >> + /* Must set UHS2 timing to identify UHS2 mode */
> >> + host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
> >> host->ios.power_mode = MMC_POWER_OFF;
> >> if (host->flags & MMC_UHS2_SD_TRAN)
> >> host->flags &= ~MMC_UHS2_SD_TRAN;
> >> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
> >> mmc_claim_host(host);
> >> mmc_detach_bus(host);
> >> sd_uhs2_power_off(host);
> >> - host->flags &= ~MMC_UHS2_SUPPORT;
> >> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> >> + host->ios.timing = MMC_TIMING_LEGACY;
> >> mmc_release_host(host);
> >> }
> >> }
> >> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
> >> err:
> >> mmc_detach_bus(host);
> >> sd_uhs2_power_off(host);
> >> - host->flags &= ~MMC_UHS2_SUPPORT;
> >> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> >> + host->ios.timing = MMC_TIMING_LEGACY;
> >> return err;
> >> }
> >
> > I wouldn't mind changing to the above. But, maybe an even better
> > option is to use the ->timing variable in the struct sdhci_host, as
> > it's there already to keep track of the current/previous timing state.
> > Would that work too?
>
> The host does not really have enough information.

Okay, let's go with the approach you suggested above/below then!

>
> >
> >>
> >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >> index 517c497112f4..d1f3318b7d3a 100644
> >> --- a/drivers/mmc/host/sdhci-uhs2.c
> >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >>
> >> /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
> >> ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> >> - if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> >> - ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> >> - ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> >> - ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> >> + if (ios->power_mode != MMC_POWER_OFF &&
> >> + (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> >> + ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> >> + ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> >> + ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
> >> ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> >> else
> >> ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> >>
> >>

Kind regards
Uffe

2023-11-17 10:50:01

by Victor Shih

[permalink] [raw]
Subject: Re: [PATCH V12 10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

On Tue, Oct 10, 2023 at 7:08 PM Ulf Hansson <[email protected]> wrote:
>
> On Tue, 10 Oct 2023 at 12:29, Adrian Hunter <[email protected]> wrote:
> >
> > On 4/10/23 11:35, Ulf Hansson wrote:
> > > On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <[email protected]> wrote:
> > >>
> > >> On 3/10/23 15:22, Ulf Hansson wrote:
> > >>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <[email protected]> wrote:
> > >>>>
> > >>>> On 3/10/23 13:30, Ulf Hansson wrote:
> > >>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <[email protected]> wrote:
> > >>>>>>
> > >>>>>> From: Victor Shih <[email protected]>
> > >>>>>>
> > >>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> > >>>>>>
> > >>>>>> Signed-off-by: Ben Chuang <[email protected]>
> > >>>>>> Signed-off-by: AKASHI Takahiro <[email protected]>
> > >>>>>> Signed-off-by: Victor Shih <[email protected]>
> > >>>>>> Acked-by: Adrian Hunter <[email protected]>
> > >>>>>> ---
> > >>>>>>
> > >>>>>> Updates in V8:
> > >>>>>> - Adjust the position of matching brackets.
> > >>>>>>
> > >>>>>> Updates in V6:
> > >>>>>> - Remove unnecessary functions and simplify code.
> > >>>>>>
> > >>>>>> ---
> > >>>>>>
> > >>>>>> drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> > >>>>>> drivers/mmc/host/sdhci-uhs2.h | 2 ++
> > >>>>>> 2 files changed, 47 insertions(+)
> > >>>>>>
> > >>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> index e339821d3504..dfc80a7f1bad 100644
> > >>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> @@ -10,7 +10,9 @@
> > >>>>>> * Author: AKASHI Takahiro <[email protected]>
> > >>>>>> */
> > >>>>>>
> > >>>>>> +#include <linux/delay.h>
> > >>>>>> #include <linux/module.h>
> > >>>>>> +#include <linux/iopoll.h>
> > >>>>>>
> > >>>>>> #include "sdhci.h"
> > >>>>>> #include "sdhci-uhs2.h"
> > >>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> > >>>>>> }
> > >>>>>> EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> > >>>>>>
> > >>>>>> +/*****************************************************************************\
> > >>>>>> + * *
> > >>>>>> + * Low level functions *
> > >>>>>> + * *
> > >>>>>> +\*****************************************************************************/
> > >>>>>> +
> > >>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> > >>>>>> +{
> > >>>>>> + return host->mmc->flags & MMC_UHS2_SUPPORT;
> > >>>>>
> > >>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> > >>>>> should be using mmc->ios.timings, which already indicates whether we
> > >>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> > >>>>> this.
> > >>>>>
> > >>>>> That said, I think we should drop the sdhci_uhs2_mode() function
> > >>>>> altogether and instead use mmc_card_uhs2(), which means we should move
> > >>>>> it to include/linux/mmc/host.h, so it becomes available for host
> > >>>>> drivers.
> > >>>>>
> > >>>>
> > >>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> > >>>> initialization fails, or the card is removed.
> > >>>>
> > >>>> So it includes re-initialization and reset when the transfer mode
> > >>>> currently transitions through MMC_TIMING_LEGACY.
> > >>>>
> > >>>> So mmc_card_uhs2() won't work correctly for the host callbacks
> > >>>> unless something is done about that.
> > >>>
> > >>> Right, thanks for clarifying!
> > >>>
> > >>> In that case I wonder if we couldn't change the way we update the
> > >>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> > >>> indicate that we have moved to UHS2.
> > >>
> > >> Perhaps something like below:
> > >>
> > >> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> > >> index aacefdd6bc9e..e39d63d46041 100644
> > >> --- a/drivers/mmc/core/sd_uhs2.c
> > >> +++ b/drivers/mmc/core/sd_uhs2.c
> > >> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
> > >>
> > >> host->ios.vdd = 0;
> > >> host->ios.clock = 0;
> > >> - host->ios.timing = MMC_TIMING_LEGACY;
> > >> + /* Must set UHS2 timing to identify UHS2 mode */
> > >> + host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
> > >> host->ios.power_mode = MMC_POWER_OFF;
> > >> if (host->flags & MMC_UHS2_SD_TRAN)
> > >> host->flags &= ~MMC_UHS2_SD_TRAN;
> > >> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
> > >> mmc_claim_host(host);
> > >> mmc_detach_bus(host);
> > >> sd_uhs2_power_off(host);
> > >> - host->flags &= ~MMC_UHS2_SUPPORT;
> > >> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> > >> + host->ios.timing = MMC_TIMING_LEGACY;
> > >> mmc_release_host(host);
> > >> }
> > >> }
> > >> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
> > >> err:
> > >> mmc_detach_bus(host);
> > >> sd_uhs2_power_off(host);
> > >> - host->flags &= ~MMC_UHS2_SUPPORT;
> > >> + /* Remove UHS2 timing to indicate the end of UHS2 mode */
> > >> + host->ios.timing = MMC_TIMING_LEGACY;
> > >> return err;
> > >> }
> > >
> > > I wouldn't mind changing to the above. But, maybe an even better
> > > option is to use the ->timing variable in the struct sdhci_host, as
> > > it's there already to keep track of the current/previous timing state.
> > > Would that work too?
> >
> > The host does not really have enough information.
>
> Okay, let's go with the approach you suggested above/below then!
>

Hi, Ulf and Adrian

I will update this in version 13.

Thanks, Victor Shih

> >
> > >
> > >>
> > >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > >> index 517c497112f4..d1f3318b7d3a 100644
> > >> --- a/drivers/mmc/host/sdhci-uhs2.c
> > >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> > >> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > >>
> > >> /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
> > >> ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > >> - if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> > >> - ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> > >> - ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> > >> - ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> > >> + if (ios->power_mode != MMC_POWER_OFF &&
> > >> + (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> > >> + ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> > >> + ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> > >> + ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
> > >> ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> > >> else
> > >> ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> > >>
> > >>
>
> Kind regards
> Uffe