[PATCH v4 0/5] brcmfmac: sdio: Deal better w/ transmission errors related to idle

[PATCH v4 0/5] brcmfmac: sdio: Deal better w/ transmission errors related to idle

[Douglas Anderson]

This series attempts to deal better with the expected transmission
errors related to the idle states (handled by the Always-On-Subsystem
or AOS) on the SDIO-based WiFi on rk3288-veyron-minnie,
rk3288-veyron-speedy, and rk3288-veyron-mickey.

Some details about those errors can be found in
<https://crbug.com/960222>, but to summarize it here: if we try to
send the wakeup command to the WiFi card at the same time it has
decided to wake up itself then it will behave badly on the SDIO bus.
This can cause timeouts or CRC errors.

When I tested on 4.19 and 4.20 these CRC errors can be seen to cause
re-tuning.  Since I am currently developing on 4.19 this was the
original problem I attempted to solve.

On mainline it turns out that you don't see the retuning errors but
you see tons of spam about timeouts trying to wakeup from sleep.  I
tracked down the commit that was causing that and have partially
reverted it here.  I have no real knowledge about Broadcom WiFi, but
the commit that was causing problems sounds (from the descriptioin) to
be a hack commit penalizing all Broadcom WiFi users because of a bug
in a Cypress SD controller.  I will let others comment if this is
truly the case and, if so, what the right solution should be.

For v3 of this series I have added 2 patches to the end of the series
to address errors that would show up on systems with these same SDIO
WiFi cards when used on controllers that do periodic retuning.  These
systems need an extra fix to prevent the retuning from happening when
the card is asleep.

Changes in v4:
- Moved to SDIO API only (Adrian, Ulf).
- Renamed to make it less generic, now retune_crc_disable (Ulf).
- Function header makes it clear host must be claimed (Ulf).
- No more WARN_ON (Ulf).
- Adjust to API rename (Adrian, Ulf).
- Moved retune hold/release to SDIO API (Adrian).
- Adjust to API rename (Adrian).

Changes in v3:
- Took out the spinlock since I believe this is all in one context.
- Expect errors for all of brcmf_sdio_kso_control() (Adrian).
- ("mmc: core: Export mmc_retune_hold_now() mmc_retune_release()") new for v3.
- ("brcmfmac: sdio: Don't tune while the card is off") new for v3.

Changes in v2:
- A full revert, not just a partial one (Arend).  ...with explicit Cc.
- Updated commit message to clarify based on discussion of v1.

Douglas Anderson (5):
  Revert "brcmfmac: disable command decode in sdio_aos"
  mmc: core: API to temporarily disable retuning for SDIO CRC errors
  brcmfmac: sdio: Disable auto-tuning around commands expected to fail
  mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()
  brcmfmac: sdio: Don't tune while the card is off

 drivers/mmc/core/core.c                       |  5 +-
 drivers/mmc/core/sdio_io.c                    | 76 +++++++++++++++++++
 .../broadcom/brcm80211/brcmfmac/sdio.c        | 17 +++--
 include/linux/mmc/core.h                      |  2 +
 include/linux/mmc/host.h                      |  1 +
 include/linux/mmc/sdio_func.h                 |  6 ++
 6 files changed, 100 insertions(+), 7 deletions(-)

-- 
2.22.0.rc2.383.gf4fbbf30c2-goog

[PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors

[Douglas Anderson]

Normally when the MMC core sees an "-EILSEQ" error returned by a host
controller then it will trigger a retuning of the card.  This is
generally a good idea.

However, if a command is expected to sometimes cause transfer errors
then these transfer errors shouldn't cause a re-tuning.  This
re-tuning will be a needless waste of time.  One example case where a
transfer is expected to cause errors is when transitioning between
idle (sometimes referred to as "sleep" in Broadcom code) and active
state on certain Broadcom WiFi SDIO cards.  Specifically if the card
was already transitioning between states when the command was sent it
could cause an error on the SDIO bus.

Let's add an API that the SDIO function drivers can call that will
temporarily disable the auto-tuning functionality.  Then we can add a
call to this in the Broadcom WiFi driver and any other driver that
might have similar needs.

NOTE: this makes the assumption that the card is already tuned well
enough that it's OK to disable the auto-retuning during one of these
error-prone situations.  Presumably the driver code performing the
error-prone transfer knows how to recover / retry from errors.  ...and
after we can get back to a state where transfers are no longer
error-prone then we can enable the auto-retuning again.  If we truly
find ourselves in a case where the card needs to be retuned sometimes
to handle one of these error-prone transfers then we can always try a
few transfers first without auto-retuning and then re-try with
auto-retuning if the first few fail.

Without this change on rk3288-veyron-minnie I periodically see this in
the logs of a machine just sitting there idle:
  dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ

Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

Changes in v4:
- Moved to SDIO API only (Adrian, Ulf).
- Renamed to make it less generic, now retune_crc_disable (Ulf).
- Function header makes it clear host must be claimed (Ulf).
- No more WARN_ON (Ulf).

Changes in v3:
- Took out the spinlock since I believe this is all in one context.

Changes in v2:
- Updated commit message to clarify based on discussion of v1.

 drivers/mmc/core/core.c       |  5 +++--
 drivers/mmc/core/sdio_io.c    | 36 +++++++++++++++++++++++++++++++++++
 include/linux/mmc/core.h      |  2 ++
 include/linux/mmc/host.h      |  1 +
 include/linux/mmc/sdio_func.h |  3 +++
 5 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 6db36dc870b5..9020cb2490f7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -144,8 +144,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
 	int err = cmd->error;
 
 	/* Flag re-tuning needed on CRC errors */
-	if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
-	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
+	if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
+	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
+	    !host->retune_crc_disable &&
 	    (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
 	    (mrq->data && mrq->data->error == -EILSEQ) ||
 	    (mrq->stop && mrq->stop->error == -EILSEQ)))
diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index f79f0b0caab8..f822a9630b0e 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -734,3 +734,39 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
+
+/**
+ *	sdio_retune_crc_disable - temporarily disable retuning on CRC errors
+ *	@func: SDIO function attached to host
+ *
+ *	If the SDIO card is known to be in a state where it might produce
+ *	CRC errors on the bus in response to commands (like if we know it is
+ *	transitioning between power states), an SDIO function driver can
+ *	call this function to temporarily disable the SD/MMC core behavior of
+ *	triggering an automatic retuning.
+ *
+ *	This function should be called while the host is claimed and the host
+ *	should remain claimed until sdio_retune_crc_enable() is called.
+ *	Specifically, the expected sequence of calls is:
+ *	- sdio_claim_host()
+ *	- sdio_retune_crc_disable()
+ *	- some number of calls like sdio_writeb() and sdio_readb()
+ *	- sdio_release_host()
+ */
+void sdio_retune_crc_disable(struct sdio_func *func)
+{
+	func->card->host->retune_crc_disable = true;
+}
+EXPORT_SYMBOL_GPL(sdio_retune_crc_disable);
+
+/**
+ *	sdio_retune_crc_enable - reneable retuning on CRC errors
+ *	@func: SDIO function attached to host
+ *
+ *	This is the compement to sdio_retune_crc_disable().
+ */
+void sdio_retune_crc_enable(struct sdio_func *func)
+{
+	func->card->host->retune_crc_disable = false;
+}
+EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 134a6483347a..02a13abf0cda 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -178,6 +178,8 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd,
 
 int mmc_hw_reset(struct mmc_host *host);
 int mmc_sw_reset(struct mmc_host *host);
+void mmc_expect_errors_begin(struct mmc_host *host);
+void mmc_expect_errors_end(struct mmc_host *host);
 void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card);
 
 #endif /* LINUX_MMC_CORE_H */
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 43d0f0c496f6..ecb7972e2423 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -398,6 +398,7 @@ struct mmc_host {
 	unsigned int		retune_now:1;	/* do re-tuning at next req */
 	unsigned int		retune_paused:1; /* re-tuning is temporarily disabled */
 	unsigned int		use_blk_mq:1;	/* use blk-mq */
+	unsigned int		retune_crc_disable:1; /* don't trigger retune upon crc */
 
 	int			rescan_disable;	/* disable card detection */
 	int			rescan_entered;	/* used with nonremovable devices */
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index e9dfdd501cd1..4820e6d09dac 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
 extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
 extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
 
+extern void sdio_retune_crc_disable(struct sdio_func *func);
+extern void sdio_retune_crc_enable(struct sdio_func *func);
+
 #endif /* LINUX_MMC_SDIO_FUNC_H */
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog

[PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Douglas Anderson]

We want SDIO drivers to be able to temporarily stop retuning when the
driver knows that the SDIO card is not in a state where retuning will
work (maybe because the card is asleep).  We'll move the relevant
functions to a place where drivers can call them.

Signed-off-by: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---

Changes in v4:
- Moved retune hold/release to SDIO API (Adrian).

Changes in v3:
- ("mmc: core: Export mmc_retune_hold_now() mmc_retune_release()") new for v3.

Changes in v2: None

 drivers/mmc/core/sdio_io.c    | 40 +++++++++++++++++++++++++++++++++++
 include/linux/mmc/sdio_func.h |  3 +++
 2 files changed, 43 insertions(+)

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index f822a9630b0e..1b6fe737bd72 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -15,6 +15,7 @@
 #include "sdio_ops.h"
 #include "core.h"
 #include "card.h"
+#include "host.h"
 
 /**
  *	sdio_claim_host - exclusively claim a bus for a certain SDIO function
@@ -770,3 +771,42 @@ void sdio_retune_crc_enable(struct sdio_func *func)
 	func->card->host->retune_crc_disable = false;
 }
 EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
+
+/**
+ *	sdio_retune_hold_now - start deferring retuning requests till release
+ *	@func: SDIO function attached to host
+ *
+ *	This function can be called if it's currently a bad time to do
+ *	a retune of the SDIO card.  Retune requests made during this time
+ *	will be held and we'll actually do the retune sometime after the
+ *	release.
+ *
+ *	This function could be useful if an SDIO card is in a power state
+ *	where it can respond to a small subset of commands that doesn't
+ *	include the retuning command.  Care should be taken when using
+ *	this function since (presumably) the retuning request we might be
+ *	deferring was made for a good reason.
+ *
+ *	This function should be called while the host is claimed.
+ */
+void sdio_retune_hold_now(struct sdio_func *func)
+{
+	mmc_retune_hold_now(func->card->host);
+}
+EXPORT_SYMBOL_GPL(sdio_retune_hold_now);
+
+/**
+ *	sdio_retune_release - signal that it's OK to retune now
+ *	@func: SDIO function attached to host
+ *
+ *	This is the complement to sdio_retune_hold_now().  Calling this
+ *	function won't make a retune happen right away but will allow
+ *	them to be scheduled normally.
+ *
+ *	This function should be called while the host is claimed.
+ */
+void sdio_retune_release(struct sdio_func *func)
+{
+	mmc_retune_release(func->card->host);
+}
+EXPORT_SYMBOL_GPL(sdio_retune_release);
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index 4820e6d09dac..5a177f7a83c3 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -170,4 +170,7 @@ extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
 extern void sdio_retune_crc_disable(struct sdio_func *func);
 extern void sdio_retune_crc_enable(struct sdio_func *func);
 
+extern void sdio_retune_hold_now(struct sdio_func *func);
+extern void sdio_retune_release(struct sdio_func *func);
+
 #endif /* LINUX_MMC_SDIO_FUNC_H */
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog

Re: [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors

[Ulf Hansson]

On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> wrote:
>
> Normally when the MMC core sees an "-EILSEQ" error returned by a host
> controller then it will trigger a retuning of the card.  This is
> generally a good idea.
>
> However, if a command is expected to sometimes cause transfer errors
> then these transfer errors shouldn't cause a re-tuning.  This
> re-tuning will be a needless waste of time.  One example case where a
> transfer is expected to cause errors is when transitioning between
> idle (sometimes referred to as "sleep" in Broadcom code) and active
> state on certain Broadcom WiFi SDIO cards.  Specifically if the card
> was already transitioning between states when the command was sent it
> could cause an error on the SDIO bus.
>
> Let's add an API that the SDIO function drivers can call that will
> temporarily disable the auto-tuning functionality.  Then we can add a
> call to this in the Broadcom WiFi driver and any other driver that
> might have similar needs.
>
> NOTE: this makes the assumption that the card is already tuned well
> enough that it's OK to disable the auto-retuning during one of these
> error-prone situations.  Presumably the driver code performing the
> error-prone transfer knows how to recover / retry from errors.  ...and
> after we can get back to a state where transfers are no longer
> error-prone then we can enable the auto-retuning again.  If we truly
> find ourselves in a case where the card needs to be retuned sometimes
> to handle one of these error-prone transfers then we can always try a
> few transfers first without auto-retuning and then re-try with
> auto-retuning if the first few fail.
>
> Without this change on rk3288-veyron-minnie I periodically see this in
> the logs of a machine just sitting there idle:
>   dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ
>
> Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
> Signed-off-by: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> ---
>
> Changes in v4:
> - Moved to SDIO API only (Adrian, Ulf).
> - Renamed to make it less generic, now retune_crc_disable (Ulf).
> - Function header makes it clear host must be claimed (Ulf).
> - No more WARN_ON (Ulf).
>
> Changes in v3:
> - Took out the spinlock since I believe this is all in one context.
>
> Changes in v2:
> - Updated commit message to clarify based on discussion of v1.
>
>  drivers/mmc/core/core.c       |  5 +++--
>  drivers/mmc/core/sdio_io.c    | 36 +++++++++++++++++++++++++++++++++++
>  include/linux/mmc/core.h      |  2 ++
>  include/linux/mmc/host.h      |  1 +
>  include/linux/mmc/sdio_func.h |  3 +++
>  5 files changed, 45 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 6db36dc870b5..9020cb2490f7 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -144,8 +144,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>         int err = cmd->error;
>
>         /* Flag re-tuning needed on CRC errors */
> -       if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> -           cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
> +       if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> +           cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
> +           !host->retune_crc_disable &&
>             (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
>             (mrq->data && mrq->data->error == -EILSEQ) ||
>             (mrq->stop && mrq->stop->error == -EILSEQ)))
> diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> index f79f0b0caab8..f822a9630b0e 100644
> --- a/drivers/mmc/core/sdio_io.c
> +++ b/drivers/mmc/core/sdio_io.c
> @@ -734,3 +734,39 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
>         return 0;
>  }
>  EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
> +
> +/**
> + *     sdio_retune_crc_disable - temporarily disable retuning on CRC errors
> + *     @func: SDIO function attached to host
> + *
> + *     If the SDIO card is known to be in a state where it might produce
> + *     CRC errors on the bus in response to commands (like if we know it is
> + *     transitioning between power states), an SDIO function driver can
> + *     call this function to temporarily disable the SD/MMC core behavior of
> + *     triggering an automatic retuning.
> + *
> + *     This function should be called while the host is claimed and the host
> + *     should remain claimed until sdio_retune_crc_enable() is called.
> + *     Specifically, the expected sequence of calls is:
> + *     - sdio_claim_host()
> + *     - sdio_retune_crc_disable()
> + *     - some number of calls like sdio_writeb() and sdio_readb()

sdio_retune_crc_enable()

> + *     - sdio_release_host()
> + */
> +void sdio_retune_crc_disable(struct sdio_func *func)
> +{
> +       func->card->host->retune_crc_disable = true;
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_crc_disable);
> +
> +/**
> + *     sdio_retune_crc_enable - reneable retuning on CRC errors

/s/reneable/re-enable

> + *     @func: SDIO function attached to host
> + *
> + *     This is the compement to sdio_retune_crc_disable().
> + */
> +void sdio_retune_crc_enable(struct sdio_func *func)
> +{
> +       func->card->host->retune_crc_disable = false;
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
> diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> index 134a6483347a..02a13abf0cda 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -178,6 +178,8 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd,
>
>  int mmc_hw_reset(struct mmc_host *host);
>  int mmc_sw_reset(struct mmc_host *host);
> +void mmc_expect_errors_begin(struct mmc_host *host);
> +void mmc_expect_errors_end(struct mmc_host *host);

Leftovers for earlier versions.

>  void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card);
>
>  #endif /* LINUX_MMC_CORE_H */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 43d0f0c496f6..ecb7972e2423 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -398,6 +398,7 @@ struct mmc_host {
>         unsigned int            retune_now:1;   /* do re-tuning at next req */
>         unsigned int            retune_paused:1; /* re-tuning is temporarily disabled */
>         unsigned int            use_blk_mq:1;   /* use blk-mq */
> +       unsigned int            retune_crc_disable:1; /* don't trigger retune upon crc */
>
>         int                     rescan_disable; /* disable card detection */
>         int                     rescan_entered; /* used with nonremovable devices */
> diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
> index e9dfdd501cd1..4820e6d09dac 100644
> --- a/include/linux/mmc/sdio_func.h
> +++ b/include/linux/mmc/sdio_func.h
> @@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
>  extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
>  extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
>
> +extern void sdio_retune_crc_disable(struct sdio_func *func);
> +extern void sdio_retune_crc_enable(struct sdio_func *func);
> +
>  #endif /* LINUX_MMC_SDIO_FUNC_H */
> --
> 2.22.0.rc2.383.gf4fbbf30c2-goog
>

Besides the minor comments, this looks good to me.

Kind regards
Uffe

Re: [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Ulf Hansson]

On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders@chromium.org> wrote:
>
> We want SDIO drivers to be able to temporarily stop retuning when the
> driver knows that the SDIO card is not in a state where retuning will
> work (maybe because the card is asleep).  We'll move the relevant
> functions to a place where drivers can call them.
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

This looks good to me.

BTW, seems like this series is best funneled via my mmc tree, no? In
such case, I need acks for the brcmfmac driver patches.

Kind regards
Uffe




> ---
>
> Changes in v4:
> - Moved retune hold/release to SDIO API (Adrian).
>
> Changes in v3:
> - ("mmc: core: Export mmc_retune_hold_now() mmc_retune_release()") new for v3.
>
> Changes in v2: None
>
>  drivers/mmc/core/sdio_io.c    | 40 +++++++++++++++++++++++++++++++++++
>  include/linux/mmc/sdio_func.h |  3 +++
>  2 files changed, 43 insertions(+)
>
> diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> index f822a9630b0e..1b6fe737bd72 100644
> --- a/drivers/mmc/core/sdio_io.c
> +++ b/drivers/mmc/core/sdio_io.c
> @@ -15,6 +15,7 @@
>  #include "sdio_ops.h"
>  #include "core.h"
>  #include "card.h"
> +#include "host.h"
>
>  /**
>   *     sdio_claim_host - exclusively claim a bus for a certain SDIO function
> @@ -770,3 +771,42 @@ void sdio_retune_crc_enable(struct sdio_func *func)
>         func->card->host->retune_crc_disable = false;
>  }
>  EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
> +
> +/**
> + *     sdio_retune_hold_now - start deferring retuning requests till release
> + *     @func: SDIO function attached to host
> + *
> + *     This function can be called if it's currently a bad time to do
> + *     a retune of the SDIO card.  Retune requests made during this time
> + *     will be held and we'll actually do the retune sometime after the
> + *     release.
> + *
> + *     This function could be useful if an SDIO card is in a power state
> + *     where it can respond to a small subset of commands that doesn't
> + *     include the retuning command.  Care should be taken when using
> + *     this function since (presumably) the retuning request we might be
> + *     deferring was made for a good reason.
> + *
> + *     This function should be called while the host is claimed.
> + */
> +void sdio_retune_hold_now(struct sdio_func *func)
> +{
> +       mmc_retune_hold_now(func->card->host);
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_hold_now);
> +
> +/**
> + *     sdio_retune_release - signal that it's OK to retune now
> + *     @func: SDIO function attached to host
> + *
> + *     This is the complement to sdio_retune_hold_now().  Calling this
> + *     function won't make a retune happen right away but will allow
> + *     them to be scheduled normally.
> + *
> + *     This function should be called while the host is claimed.
> + */
> +void sdio_retune_release(struct sdio_func *func)
> +{
> +       mmc_retune_release(func->card->host);
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_release);
> diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
> index 4820e6d09dac..5a177f7a83c3 100644
> --- a/include/linux/mmc/sdio_func.h
> +++ b/include/linux/mmc/sdio_func.h
> @@ -170,4 +170,7 @@ extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
>  extern void sdio_retune_crc_disable(struct sdio_func *func);
>  extern void sdio_retune_crc_enable(struct sdio_func *func);
>
> +extern void sdio_retune_hold_now(struct sdio_func *func);
> +extern void sdio_retune_release(struct sdio_func *func);
> +
>  #endif /* LINUX_MMC_SDIO_FUNC_H */
> --
> 2.22.0.rc2.383.gf4fbbf30c2-goog
>

Re: [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Doug Anderson]

Hi,

On Fri, Jun 14, 2019 at 5:10 AM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders@chromium.org> wrote:
> >
> > We want SDIO drivers to be able to temporarily stop retuning when the
> > driver knows that the SDIO card is not in a state where retuning will
> > work (maybe because the card is asleep).  We'll move the relevant
> > functions to a place where drivers can call them.
> >
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
>
> This looks good to me.
>
> BTW, seems like this series is best funneled via my mmc tree, no? In
> such case, I need acks for the brcmfmac driver patches.

For patch #1 I think it could just go in directly to the wireless
tree.  It should be fine to land the rest of the patches separately.

For patch #2 - #5 then what you say makes sense to me.  I suppose
you'd want at least a Reviewed-by from Arend and an Ack from Kalle on
the Broadcom patches?

I'd also suggest that we Cc stable explicitly when applying.  That's
easy for #2 and #3 since they have a Fixes tag.  For #4 and #5 I guess
the question is how far back to go.  Maybe Adrian has an opinion here
since I think he's the one who experienced these problems.


Thanks!
-Doug

Re: [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors

[Doug Anderson]

Hi,

On Fri, Jun 14, 2019 at 5:04 AM Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
>
> On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> wrote:
> >
> > Normally when the MMC core sees an "-EILSEQ" error returned by a host
> > controller then it will trigger a retuning of the card.  This is
> > generally a good idea.
> >
> > However, if a command is expected to sometimes cause transfer errors
> > then these transfer errors shouldn't cause a re-tuning.  This
> > re-tuning will be a needless waste of time.  One example case where a
> > transfer is expected to cause errors is when transitioning between
> > idle (sometimes referred to as "sleep" in Broadcom code) and active
> > state on certain Broadcom WiFi SDIO cards.  Specifically if the card
> > was already transitioning between states when the command was sent it
> > could cause an error on the SDIO bus.
> >
> > Let's add an API that the SDIO function drivers can call that will
> > temporarily disable the auto-tuning functionality.  Then we can add a
> > call to this in the Broadcom WiFi driver and any other driver that
> > might have similar needs.
> >
> > NOTE: this makes the assumption that the card is already tuned well
> > enough that it's OK to disable the auto-retuning during one of these
> > error-prone situations.  Presumably the driver code performing the
> > error-prone transfer knows how to recover / retry from errors.  ...and
> > after we can get back to a state where transfers are no longer
> > error-prone then we can enable the auto-retuning again.  If we truly
> > find ourselves in a case where the card needs to be retuned sometimes
> > to handle one of these error-prone transfers then we can always try a
> > few transfers first without auto-retuning and then re-try with
> > auto-retuning if the first few fail.
> >
> > Without this change on rk3288-veyron-minnie I periodically see this in
> > the logs of a machine just sitting there idle:
> >   dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ
> >
> > Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
> > Signed-off-by: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> > ---
> >
> > Changes in v4:
> > - Moved to SDIO API only (Adrian, Ulf).
> > - Renamed to make it less generic, now retune_crc_disable (Ulf).
> > - Function header makes it clear host must be claimed (Ulf).
> > - No more WARN_ON (Ulf).
> >
> > Changes in v3:
> > - Took out the spinlock since I believe this is all in one context.
> >
> > Changes in v2:
> > - Updated commit message to clarify based on discussion of v1.
> >
> >  drivers/mmc/core/core.c       |  5 +++--
> >  drivers/mmc/core/sdio_io.c    | 36 +++++++++++++++++++++++++++++++++++
> >  include/linux/mmc/core.h      |  2 ++
> >  include/linux/mmc/host.h      |  1 +
> >  include/linux/mmc/sdio_func.h |  3 +++
> >  5 files changed, 45 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> > index 6db36dc870b5..9020cb2490f7 100644
> > --- a/drivers/mmc/core/core.c
> > +++ b/drivers/mmc/core/core.c
> > @@ -144,8 +144,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
> >         int err = cmd->error;
> >
> >         /* Flag re-tuning needed on CRC errors */
> > -       if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> > -           cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
> > +       if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> > +           cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
> > +           !host->retune_crc_disable &&
> >             (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
> >             (mrq->data && mrq->data->error == -EILSEQ) ||
> >             (mrq->stop && mrq->stop->error == -EILSEQ)))
> > diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> > index f79f0b0caab8..f822a9630b0e 100644
> > --- a/drivers/mmc/core/sdio_io.c
> > +++ b/drivers/mmc/core/sdio_io.c
> > @@ -734,3 +734,39 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
> >         return 0;
> >  }
> >  EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
> > +
> > +/**
> > + *     sdio_retune_crc_disable - temporarily disable retuning on CRC errors
> > + *     @func: SDIO function attached to host
> > + *
> > + *     If the SDIO card is known to be in a state where it might produce
> > + *     CRC errors on the bus in response to commands (like if we know it is
> > + *     transitioning between power states), an SDIO function driver can
> > + *     call this function to temporarily disable the SD/MMC core behavior of
> > + *     triggering an automatic retuning.
> > + *
> > + *     This function should be called while the host is claimed and the host
> > + *     should remain claimed until sdio_retune_crc_enable() is called.
> > + *     Specifically, the expected sequence of calls is:
> > + *     - sdio_claim_host()
> > + *     - sdio_retune_crc_disable()
> > + *     - some number of calls like sdio_writeb() and sdio_readb()
>
> sdio_retune_crc_enable()
>
> > + *     - sdio_release_host()
> > + */
> > +void sdio_retune_crc_disable(struct sdio_func *func)
> > +{
> > +       func->card->host->retune_crc_disable = true;
> > +}
> > +EXPORT_SYMBOL_GPL(sdio_retune_crc_disable);
> > +
> > +/**
> > + *     sdio_retune_crc_enable - reneable retuning on CRC errors
>
> /s/reneable/re-enable
>
> > + *     @func: SDIO function attached to host
> > + *
> > + *     This is the compement to sdio_retune_crc_disable().
> > + */
> > +void sdio_retune_crc_enable(struct sdio_func *func)
> > +{
> > +       func->card->host->retune_crc_disable = false;
> > +}
> > +EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
> > diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> > index 134a6483347a..02a13abf0cda 100644
> > --- a/include/linux/mmc/core.h
> > +++ b/include/linux/mmc/core.h
> > @@ -178,6 +178,8 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd,
> >
> >  int mmc_hw_reset(struct mmc_host *host);
> >  int mmc_sw_reset(struct mmc_host *host);
> > +void mmc_expect_errors_begin(struct mmc_host *host);
> > +void mmc_expect_errors_end(struct mmc_host *host);
>
> Leftovers for earlier versions.

Oops!


> >  void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card);
> >
> >  #endif /* LINUX_MMC_CORE_H */
> > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> > index 43d0f0c496f6..ecb7972e2423 100644
> > --- a/include/linux/mmc/host.h
> > +++ b/include/linux/mmc/host.h
> > @@ -398,6 +398,7 @@ struct mmc_host {
> >         unsigned int            retune_now:1;   /* do re-tuning at next req */
> >         unsigned int            retune_paused:1; /* re-tuning is temporarily disabled */
> >         unsigned int            use_blk_mq:1;   /* use blk-mq */
> > +       unsigned int            retune_crc_disable:1; /* don't trigger retune upon crc */
> >
> >         int                     rescan_disable; /* disable card detection */
> >         int                     rescan_entered; /* used with nonremovable devices */
> > diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
> > index e9dfdd501cd1..4820e6d09dac 100644
> > --- a/include/linux/mmc/sdio_func.h
> > +++ b/include/linux/mmc/sdio_func.h
> > @@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
> >  extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
> >  extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
> >
> > +extern void sdio_retune_crc_disable(struct sdio_func *func);
> > +extern void sdio_retune_crc_enable(struct sdio_func *func);
> > +
> >  #endif /* LINUX_MMC_SDIO_FUNC_H */
> > --
> > 2.22.0.rc2.383.gf4fbbf30c2-goog
> >
>
> Besides the minor comments, this looks good to me.

Thank you for the reviews!

I'll plan to send a v5 on my Monday with the fixes assuming no new
heated discussion starts up.  If it's less work for you, I'm also
happy if you just want to make the trivial fixes yourself when
applying.

-Doug

Re: [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Arend Van Spriel]

On June 14, 2019 6:38:51 PM Doug Anderson <dianders@chromium.org> wrote:

> Hi,
>
> On Fri, Jun 14, 2019 at 5:10 AM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>
>> On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders@chromium.org> wrote:
>> >
>> > We want SDIO drivers to be able to temporarily stop retuning when the
>> > driver knows that the SDIO card is not in a state where retuning will
>> > work (maybe because the card is asleep).  We'll move the relevant
>> > functions to a place where drivers can call them.
>> >
>> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
>>
>> This looks good to me.
>>
>> BTW, seems like this series is best funneled via my mmc tree, no? In
>> such case, I need acks for the brcmfmac driver patches.
>
> For patch #1 I think it could just go in directly to the wireless
> tree.  It should be fine to land the rest of the patches separately.

Agree.

> For patch #2 - #5 then what you say makes sense to me.  I suppose
> you'd want at least a Reviewed-by from Arend and an Ack from Kalle on
> the Broadcom patches?

Will do.

> I'd also suggest that we Cc stable explicitly when applying.  That's
> easy for #2 and #3 since they have a Fixes tag.  For #4 and #5 I guess
> the question is how far back to go.  Maybe Adrian has an opinion here
> since I think he's the one who experienced these problems.

I see if I can come up wit a fixes tag for #5.

Regards,
Arend

Re: [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors

[Ulf Hansson]

[...]

> > > --- a/include/linux/mmc/sdio_func.h
> > > +++ b/include/linux/mmc/sdio_func.h
> > > @@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
> > >  extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
> > >  extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
> > >
> > > +extern void sdio_retune_crc_disable(struct sdio_func *func);
> > > +extern void sdio_retune_crc_enable(struct sdio_func *func);
> > > +
> > >  #endif /* LINUX_MMC_SDIO_FUNC_H */
> > > --
> > > 2.22.0.rc2.383.gf4fbbf30c2-goog
> > >
> >
> > Besides the minor comments, this looks good to me.
>
> Thank you for the reviews!
>
> I'll plan to send a v5 on my Monday with the fixes assuming no new
> heated discussion starts up.  If it's less work for you, I'm also
> happy if you just want to make the trivial fixes yourself when
> applying.

It really doesn't matter to me, feel free to pick the option you
prefer. At this point I am just awaiting acks for the broadcom patces
and some clarity of what stable releases we should target for
non-tagged patches.

Kind regards
Uffe

Re: [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors

[Adrian Hunter]

On 14/06/19 2:41 AM, Douglas Anderson wrote:
> Normally when the MMC core sees an "-EILSEQ" error returned by a host
> controller then it will trigger a retuning of the card.  This is
> generally a good idea.
> 
> However, if a command is expected to sometimes cause transfer errors
> then these transfer errors shouldn't cause a re-tuning.  This
> re-tuning will be a needless waste of time.  One example case where a
> transfer is expected to cause errors is when transitioning between
> idle (sometimes referred to as "sleep" in Broadcom code) and active
> state on certain Broadcom WiFi SDIO cards.  Specifically if the card
> was already transitioning between states when the command was sent it
> could cause an error on the SDIO bus.
> 
> Let's add an API that the SDIO function drivers can call that will
> temporarily disable the auto-tuning functionality.  Then we can add a
> call to this in the Broadcom WiFi driver and any other driver that
> might have similar needs.
> 
> NOTE: this makes the assumption that the card is already tuned well
> enough that it's OK to disable the auto-retuning during one of these
> error-prone situations.  Presumably the driver code performing the
> error-prone transfer knows how to recover / retry from errors.  ...and
> after we can get back to a state where transfers are no longer
> error-prone then we can enable the auto-retuning again.  If we truly
> find ourselves in a case where the card needs to be retuned sometimes
> to handle one of these error-prone transfers then we can always try a
> few transfers first without auto-retuning and then re-try with
> auto-retuning if the first few fail.
> 
> Without this change on rk3288-veyron-minnie I periodically see this in
> the logs of a machine just sitting there idle:
>   dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ
> 
> Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Not withstanding Ulf's comments:

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> 
> Changes in v4:
> - Moved to SDIO API only (Adrian, Ulf).
> - Renamed to make it less generic, now retune_crc_disable (Ulf).
> - Function header makes it clear host must be claimed (Ulf).
> - No more WARN_ON (Ulf).
> 
> Changes in v3:
> - Took out the spinlock since I believe this is all in one context.
> 
> Changes in v2:
> - Updated commit message to clarify based on discussion of v1.
> 
>  drivers/mmc/core/core.c       |  5 +++--
>  drivers/mmc/core/sdio_io.c    | 36 +++++++++++++++++++++++++++++++++++
>  include/linux/mmc/core.h      |  2 ++
>  include/linux/mmc/host.h      |  1 +
>  include/linux/mmc/sdio_func.h |  3 +++
>  5 files changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 6db36dc870b5..9020cb2490f7 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -144,8 +144,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq)
>  	int err = cmd->error;
>  
>  	/* Flag re-tuning needed on CRC errors */
> -	if ((cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> -	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) &&
> +	if (cmd->opcode != MMC_SEND_TUNING_BLOCK &&
> +	    cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 &&
> +	    !host->retune_crc_disable &&
>  	    (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) ||
>  	    (mrq->data && mrq->data->error == -EILSEQ) ||
>  	    (mrq->stop && mrq->stop->error == -EILSEQ)))
> diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> index f79f0b0caab8..f822a9630b0e 100644
> --- a/drivers/mmc/core/sdio_io.c
> +++ b/drivers/mmc/core/sdio_io.c
> @@ -734,3 +734,39 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags)
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags);
> +
> +/**
> + *	sdio_retune_crc_disable - temporarily disable retuning on CRC errors
> + *	@func: SDIO function attached to host
> + *
> + *	If the SDIO card is known to be in a state where it might produce
> + *	CRC errors on the bus in response to commands (like if we know it is
> + *	transitioning between power states), an SDIO function driver can
> + *	call this function to temporarily disable the SD/MMC core behavior of
> + *	triggering an automatic retuning.
> + *
> + *	This function should be called while the host is claimed and the host
> + *	should remain claimed until sdio_retune_crc_enable() is called.
> + *	Specifically, the expected sequence of calls is:
> + *	- sdio_claim_host()
> + *	- sdio_retune_crc_disable()
> + *	- some number of calls like sdio_writeb() and sdio_readb()
> + *	- sdio_release_host()
> + */
> +void sdio_retune_crc_disable(struct sdio_func *func)
> +{
> +	func->card->host->retune_crc_disable = true;
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_crc_disable);
> +
> +/**
> + *	sdio_retune_crc_enable - reneable retuning on CRC errors
> + *	@func: SDIO function attached to host
> + *
> + *	This is the compement to sdio_retune_crc_disable().
> + */
> +void sdio_retune_crc_enable(struct sdio_func *func)
> +{
> +	func->card->host->retune_crc_disable = false;
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
> diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
> index 134a6483347a..02a13abf0cda 100644
> --- a/include/linux/mmc/core.h
> +++ b/include/linux/mmc/core.h
> @@ -178,6 +178,8 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd,
>  
>  int mmc_hw_reset(struct mmc_host *host);
>  int mmc_sw_reset(struct mmc_host *host);
> +void mmc_expect_errors_begin(struct mmc_host *host);
> +void mmc_expect_errors_end(struct mmc_host *host);
>  void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card);
>  
>  #endif /* LINUX_MMC_CORE_H */
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 43d0f0c496f6..ecb7972e2423 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -398,6 +398,7 @@ struct mmc_host {
>  	unsigned int		retune_now:1;	/* do re-tuning at next req */
>  	unsigned int		retune_paused:1; /* re-tuning is temporarily disabled */
>  	unsigned int		use_blk_mq:1;	/* use blk-mq */
> +	unsigned int		retune_crc_disable:1; /* don't trigger retune upon crc */
>  
>  	int			rescan_disable;	/* disable card detection */
>  	int			rescan_entered;	/* used with nonremovable devices */
> diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
> index e9dfdd501cd1..4820e6d09dac 100644
> --- a/include/linux/mmc/sdio_func.h
> +++ b/include/linux/mmc/sdio_func.h
> @@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b,
>  extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func);
>  extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
>  
> +extern void sdio_retune_crc_disable(struct sdio_func *func);
> +extern void sdio_retune_crc_enable(struct sdio_func *func);
> +
>  #endif /* LINUX_MMC_SDIO_FUNC_H */
> 

Re: [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Adrian Hunter]

On 14/06/19 2:41 AM, Douglas Anderson wrote:
> We want SDIO drivers to be able to temporarily stop retuning when the
> driver knows that the SDIO card is not in a state where retuning will
> work (maybe because the card is asleep).  We'll move the relevant
> functions to a place where drivers can call them.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> 
> Changes in v4:
> - Moved retune hold/release to SDIO API (Adrian).
> 
> Changes in v3:
> - ("mmc: core: Export mmc_retune_hold_now() mmc_retune_release()") new for v3.
> 
> Changes in v2: None
> 
>  drivers/mmc/core/sdio_io.c    | 40 +++++++++++++++++++++++++++++++++++
>  include/linux/mmc/sdio_func.h |  3 +++
>  2 files changed, 43 insertions(+)
> 
> diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
> index f822a9630b0e..1b6fe737bd72 100644
> --- a/drivers/mmc/core/sdio_io.c
> +++ b/drivers/mmc/core/sdio_io.c
> @@ -15,6 +15,7 @@
>  #include "sdio_ops.h"
>  #include "core.h"
>  #include "card.h"
> +#include "host.h"
>  
>  /**
>   *	sdio_claim_host - exclusively claim a bus for a certain SDIO function
> @@ -770,3 +771,42 @@ void sdio_retune_crc_enable(struct sdio_func *func)
>  	func->card->host->retune_crc_disable = false;
>  }
>  EXPORT_SYMBOL_GPL(sdio_retune_crc_enable);
> +
> +/**
> + *	sdio_retune_hold_now - start deferring retuning requests till release
> + *	@func: SDIO function attached to host
> + *
> + *	This function can be called if it's currently a bad time to do
> + *	a retune of the SDIO card.  Retune requests made during this time
> + *	will be held and we'll actually do the retune sometime after the
> + *	release.
> + *
> + *	This function could be useful if an SDIO card is in a power state
> + *	where it can respond to a small subset of commands that doesn't
> + *	include the retuning command.  Care should be taken when using
> + *	this function since (presumably) the retuning request we might be
> + *	deferring was made for a good reason.
> + *
> + *	This function should be called while the host is claimed.
> + */
> +void sdio_retune_hold_now(struct sdio_func *func)
> +{
> +	mmc_retune_hold_now(func->card->host);
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_hold_now);
> +
> +/**
> + *	sdio_retune_release - signal that it's OK to retune now
> + *	@func: SDIO function attached to host
> + *
> + *	This is the complement to sdio_retune_hold_now().  Calling this
> + *	function won't make a retune happen right away but will allow
> + *	them to be scheduled normally.
> + *
> + *	This function should be called while the host is claimed.
> + */
> +void sdio_retune_release(struct sdio_func *func)
> +{
> +	mmc_retune_release(func->card->host);
> +}
> +EXPORT_SYMBOL_GPL(sdio_retune_release);
> diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
> index 4820e6d09dac..5a177f7a83c3 100644
> --- a/include/linux/mmc/sdio_func.h
> +++ b/include/linux/mmc/sdio_func.h
> @@ -170,4 +170,7 @@ extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags);
>  extern void sdio_retune_crc_disable(struct sdio_func *func);
>  extern void sdio_retune_crc_enable(struct sdio_func *func);
>  
> +extern void sdio_retune_hold_now(struct sdio_func *func);
> +extern void sdio_retune_release(struct sdio_func *func);
> +
>  #endif /* LINUX_MMC_SDIO_FUNC_H */
> 

Re: [PATCH v4 4/5] mmc: core: Add sdio_retune_hold_now() and sdio_retune_release()

[Adrian Hunter]

On 14/06/19 7:38 PM, Doug Anderson wrote:
> Hi,
> 
> On Fri, Jun 14, 2019 at 5:10 AM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>
>> On Fri, 14 Jun 2019 at 01:42, Douglas Anderson <dianders@chromium.org> wrote:
>>>
>>> We want SDIO drivers to be able to temporarily stop retuning when the
>>> driver knows that the SDIO card is not in a state where retuning will
>>> work (maybe because the card is asleep).  We'll move the relevant
>>> functions to a place where drivers can call them.
>>>
>>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>>
>> This looks good to me.
>>
>> BTW, seems like this series is best funneled via my mmc tree, no? In
>> such case, I need acks for the brcmfmac driver patches.
> 
> For patch #1 I think it could just go in directly to the wireless
> tree.  It should be fine to land the rest of the patches separately.
> 
> For patch #2 - #5 then what you say makes sense to me.  I suppose
> you'd want at least a Reviewed-by from Arend and an Ack from Kalle on
> the Broadcom patches?
> 
> I'd also suggest that we Cc stable explicitly when applying.  That's
> easy for #2 and #3 since they have a Fixes tag.  For #4 and #5 I guess
> the question is how far back to go.  Maybe Adrian has an opinion here
> since I think he's the one who experienced these problems.

V4 seemed to apply cleanly back to v4.18