Messages in this thread | | | Subject | Re: [PATCH 2/2] mmc: Add mmc_force_detect_change_begin / _end functions | From | Shawn Lin <> | Date | Sat, 22 Jul 2017 22:07:58 +0800 |
| |
invite Jack from expressif
在 2017/7/21 22:35, Quentin Schulz 写道: > From: Hans de Goede <hdegoede@redhat.com> > > Some sdio devices have a multiple stage bring-up process. Specifically > the esp8089 (for which an out of tree driver is available) loads firmware > on the first call to its sdio-drivers' probe function and then resets > the device causing it to reboot from its RAM with the new firmware. >
Nice to see finally someone get into here!
I was bringing up ESP8089 for rockchip platforms 4 yeas ago with Jack from espressif, the ESP8089 RD team, face 2 face. And I forgot most the details but it seems indeed the limitation of RAM size so that it has to use 2 stages boot-up method.
I hople Jack could give some suggestion or details about this.
> When this sdio device reboots it comes back up in 1 bit 400 KHz mode > again, and we need to walk through the whole ios negatiation and sdio setup > again. > > There are 2 problems with this: > > 1) Typically these devices are soldered onto some (ARM) tablet / SBC > PCB and as such are described in devicetree as "non-removable", which > causes the mmc-core to scan them only once and not poll for the device > dropping of the bus. Normally this is the right thing todo but in the > eso8089 example we need the mmc-core to notice the module has disconnected > (since it is now in 1 bit mode again it will not talk to the host in 4 bit > mode). This can be worked around by using "broken-cd" in devicetree > instead of "non-removable", but that is not a proper fix since the device > really is non-removable. > > 2) When the mmc-core detects the device has disconnected it will poweroff > the device, causing the RAM loaded firmware to be lost. This can be worked > around in devicetree by using regulator-always-on (and avoiding the use of > mmc-pwrseq), but again that is more of a hack then a proper fix. > > This commmit fixes 1) by adding a mmc_force_detect_change function which > will cause scanning for device removal / insertion until a new device is > detected. 2) Is fixed by a keep_power flag to the mmc_force_detect_change > function which when set causes the mmc-core to keep the power to the device > on during the rescan. > > Cc: Icenowy Zheng <icenowy@aosc.xyz> > Cc: Maxime Ripard <maxime.ripard@free-electrons.com> > Cc: Chen-Yu Tsai <wens@csie.org> > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > drivers/mmc/core/core.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- > include/linux/mmc/host.h | 7 +++++++ > 2 files changed, 49 insertions(+), 5 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 26431267a3e2..103badde910b 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -1620,8 +1620,11 @@ int mmc_select_drive_strength(struct mmc_card *card, unsigned int max_dtr, > */ > void mmc_power_up(struct mmc_host *host, u32 ocr) > { > - if (host->ios.power_mode == MMC_POWER_ON) > + if (host->ios.power_mode == MMC_POWER_ON) { > + if (host->ios.clock == 0) > + goto set_clock; > return; > + } > > mmc_pwrseq_pre_power_on(host); > > @@ -1646,6 +1649,7 @@ void mmc_power_up(struct mmc_host *host, u32 ocr) > > mmc_pwrseq_post_power_on(host); > > +set_clock: > host->ios.clock = host->f_init; > > host->ios.power_mode = MMC_POWER_ON; > @@ -1663,6 +1667,11 @@ void mmc_power_off(struct mmc_host *host) > if (host->ios.power_mode == MMC_POWER_OFF) > return; > > + if (host->rescan_keep_power) { > + mmc_set_clock(host, 0); > + return; > + } > + > mmc_pwrseq_power_off(host); > > host->ios.clock = 0; > @@ -1804,6 +1813,27 @@ void mmc_detect_change(struct mmc_host *host, unsigned long delay) > } > EXPORT_SYMBOL(mmc_detect_change); > > +/** > + * mmc_force_detect_change - force rescanning of a MMC socket even if > + * it is non-removable > + * @host: host to rescan > + * @delay: optional delay to wait before detection (jiffies) > + * @keep_power: if set do not turn of vdd / call pwrseq_off during rescan > + * > + * MMC drivers which need non-removable sdio devices to be rescanned > + * (e.g. because the device reboots its fw after a firmware upload), > + * can call this to force scanning the MMC socket for changes, even > + * if it is non-removable. > + */ > +void mmc_force_detect_change(struct mmc_host *host, unsigned long delay, > + bool keep_power) > +{ > + host->rescan_force = 1; > + host->rescan_keep_power = keep_power; > + _mmc_detect_change(host, delay, false); > +} > +EXPORT_SYMBOL(mmc_force_detect_change); > + > void mmc_init_erase(struct mmc_card *card) > { > unsigned int sz; > @@ -2566,7 +2596,8 @@ void mmc_rescan(struct work_struct *work) > return; > > /* If there is a non-removable card registered, only scan once */ > - if (!mmc_card_is_removable(host) && host->rescan_entered) > + if (!mmc_card_is_removable(host) && host->rescan_entered && > + !host->rescan_force) > return; > host->rescan_entered = 1; > > @@ -2583,7 +2614,8 @@ void mmc_rescan(struct work_struct *work) > * if there is a _removable_ card registered, check whether it is > * still present > */ > - if (host->bus_ops && !host->bus_dead && mmc_card_is_removable(host)) > + if (host->bus_ops && !host->bus_dead && > + (mmc_card_is_removable(host) || host->rescan_force)) > host->bus_ops->detect(host); > > host->detect_change = 0; > @@ -2616,15 +2648,20 @@ void mmc_rescan(struct work_struct *work) > } > > for (i = 0; i < ARRAY_SIZE(freqs); i++) { > - if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min))) > + if (!mmc_rescan_try_freq(host, max(freqs[i], host->f_min))) { > + if (host->rescan_force) { > + host->rescan_force = 0; > + host->rescan_keep_power = 0; > + } > break; > + } > if (freqs[i] <= host->f_min) > break; > } > mmc_release_host(host); > > out: > - if (host->caps & MMC_CAP_NEEDS_POLL) > + if ((host->caps & MMC_CAP_NEEDS_POLL) || host->rescan_force) > mmc_schedule_delayed_work(&host->detect, HZ); > } > > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index ebd1cebbef0c..d56d79867bbd 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -338,6 +338,8 @@ struct mmc_host { > > int rescan_disable; /* disable card detection */ > int rescan_entered; /* used with nonremovable devices */ > + int rescan_force; /* force rescan of (nonremovable) devices */ > + int rescan_keep_power; /* Do not power off card */ > > int need_retune; /* re-tuning is needed */ > int hold_retune; /* hold off re-tuning */ > @@ -420,6 +422,11 @@ int mmc_power_save_host(struct mmc_host *host); > int mmc_power_restore_host(struct mmc_host *host); > > void mmc_detect_change(struct mmc_host *, unsigned long delay); > + > +/* HdG: HACK HACK HACK do not upstream */ > +#define MMC_HAS_FORCE_DETECT_CHANGE > +void mmc_force_detect_change(struct mmc_host *host, unsigned long delay, > + bool keep_power); > void mmc_request_done(struct mmc_host *, struct mmc_request *); > void mmc_command_done(struct mmc_host *host, struct mmc_request *mrq); > >
-- Best Regards Shawn Lin
| |