Hi, These patches will be further taken by Sarthak. Thanks, Satya -----Original Message----- From: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Sent: Wednesday, April 27, 2022 1:06 PM To: quic_spathi <quic_spathi@xxxxxxxxxxx> Cc: avri.altman@xxxxxxx; linus.walleij@xxxxxxxxxx; shawn.lin@xxxxxxxxxxxxxx; merez@xxxxxxxxxxxxxx; s.shtylyov@xxxxxx; huijin.park@xxxxxxxxxxx; briannorris@xxxxxxxxxxxx; digetx@xxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>; Shaik Sajida Bhanu <sbhanu@xxxxxxxxxxxxxx>; Kamasali Satyanarayan (Consultant) (QUIC) <quic_kamasali@xxxxxxxxxxx> Subject: Re: [PATCH V1] mmc: core: Add partial initialization support On Tue, 26 Apr 2022 at 11:04, Srinivasarao Pathipati <quic_spathi@xxxxxxxxxxx> wrote: > > From: Maya Erez <merez@xxxxxxxxxxxxxx> > > This change adds the ability to partially initialize the MMC card by > using card Sleep/Awake sequence (CMD5). > Card will be sent to Sleep state during runtime/system suspend and > will be woken up during runtime/system resume. > By using this sequence the card doesn't need full initialization which > gives time reduction in system/runtime resume path. > > Signed-off-by: Maya Erez <merez@xxxxxxxxxxxxxx> > Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx> > Signed-off-by: Shaik Sajida Bhanu <sbhanu@xxxxxxxxxxxxxx> > Signed-off-by: kamasali <quic_kamasali@xxxxxxxxxxx> > Signed-off-by: Srinivasarao Pathipati <quic_spathi@xxxxxxxxxxx> It seems like this patch has been posted before [1]. Let me repeat my question sent back then. It would be nice if you could provide some more exact numbers of what the gain is for a couple of different eMMCs, to justify the change. Can you please do that? Kind regards Uffe [1] https://patchwork.kernel.org/project/linux-mmc/patch/1591277381-7734-1-git-send-email-vbadigan@xxxxxxxxxxxxxx/ > --- > drivers/mmc/core/mmc.c | 149 ++++++++++++++++++++++++++++++++++++++++++++--- > include/linux/mmc/card.h | 4 ++ > include/linux/mmc/host.h | 2 + > 3 files changed, 146 insertions(+), 9 deletions(-) > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index > 9ab915b..8691c00 100644 > --- a/drivers/mmc/core/mmc.c > +++ b/drivers/mmc/core/mmc.c > @@ -1942,7 +1942,14 @@ static int mmc_sleep_busy_cb(void *cb_data, bool *busy) > return 0; > } > > -static int mmc_sleep(struct mmc_host *host) > +static int mmc_can_sleepawake(struct mmc_host *host) { > + return host && (host->caps2 & MMC_CAP2_SLEEP_AWAKE) && host->card && > + (host->card->ext_csd.rev >= 3); > + > +} > + > +static int mmc_sleepawake(struct mmc_host *host, bool sleep) > { > struct mmc_command cmd = {}; > struct mmc_card *card = host->card; @@ -1953,14 +1960,17 @@ > static int mmc_sleep(struct mmc_host *host) > /* Re-tuning can't be done once the card is deselected */ > mmc_retune_hold(host); > > - err = mmc_deselect_cards(host); > - if (err) > - goto out_release; > + if (sleep) { > + err = mmc_deselect_cards(host); > + if (err) > + goto out_release; > + } > > cmd.opcode = MMC_SLEEP_AWAKE; > cmd.arg = card->rca << 16; > - cmd.arg |= 1 << 15; > use_r1b_resp = mmc_prepare_busy_cmd(host, &cmd, timeout_ms); > + if (sleep) > + cmd.arg |= 1 << 15; > > err = mmc_wait_for_cmd(host, &cmd, 0); > if (err) > @@ -1982,6 +1992,9 @@ static int mmc_sleep(struct mmc_host *host) > > err = __mmc_poll_for_busy(host, 0, timeout_ms, > &mmc_sleep_busy_cb, host); > > + if (!sleep) > + err = mmc_select_card(card); > + > out_release: > mmc_retune_release(host); > return err; > @@ -2080,6 +2093,66 @@ static int _mmc_flush_cache(struct mmc_host *host) > pr_err("%s: cache flush error %d\n", > mmc_hostname(host), err); > } > + return err; > +} > + > +static int mmc_cache_card_ext_csd(struct mmc_host *host) { > + int err; > + u8 *ext_csd; > + struct mmc_card *card = host->card; > + > + err = mmc_get_ext_csd(card, &ext_csd); > + if (err || !ext_csd) { > + pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n", > + mmc_hostname(host), __func__, err); > + return err; > + } > + /* only cache read/write fields that the sw changes */ > + card->ext_csd.raw_ext_csd_cmdq = ext_csd[EXT_CSD_CMDQ_MODE_EN]; > + card->ext_csd.raw_ext_csd_cache_ctrl = ext_csd[EXT_CSD_CACHE_CTRL]; > + card->ext_csd.raw_ext_csd_bus_width = ext_csd[EXT_CSD_BUS_WIDTH]; > + card->ext_csd.raw_ext_csd_hs_timing = > + ext_csd[EXT_CSD_HS_TIMING]; > + > + kfree(ext_csd); > + > + return 0; > +} > + > +static int mmc_test_awake_ext_csd(struct mmc_host *host) { > + int err; > + u8 *ext_csd; > + struct mmc_card *card = host->card; > + > + err = mmc_get_ext_csd(card, &ext_csd); > + if (err) { > + pr_err("%s: %s: mmc_get_ext_csd failed (%d)\n", > + mmc_hostname(host), __func__, err); > + return err; > + } > + > + /* only compare read/write fields that the sw changes */ > + pr_debug("%s: %s: type(cached:current) cmdq(%d:%d) cache_ctrl(%d:%d) bus_width (%d:%d) timing(%d:%d)\n", > + mmc_hostname(host), __func__, > + card->ext_csd.raw_ext_csd_cmdq, > + ext_csd[EXT_CSD_CMDQ_MODE_EN], > + card->ext_csd.raw_ext_csd_cache_ctrl, > + ext_csd[EXT_CSD_CACHE_CTRL], > + card->ext_csd.raw_ext_csd_bus_width, > + ext_csd[EXT_CSD_BUS_WIDTH], > + card->ext_csd.raw_ext_csd_hs_timing, > + ext_csd[EXT_CSD_HS_TIMING]); > + err = !((card->ext_csd.raw_ext_csd_cmdq == > + ext_csd[EXT_CSD_CMDQ_MODE_EN]) && > + (card->ext_csd.raw_ext_csd_cache_ctrl == > + ext_csd[EXT_CSD_CACHE_CTRL]) && > + (card->ext_csd.raw_ext_csd_bus_width == > + ext_csd[EXT_CSD_BUS_WIDTH]) && > + (card->ext_csd.raw_ext_csd_hs_timing == > + ext_csd[EXT_CSD_HS_TIMING])); > + > + kfree(ext_csd); > > return err; > } > @@ -2103,8 +2176,12 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend) > ((host->caps2 & MMC_CAP2_FULL_PWR_CYCLE) || !is_suspend || > (host->caps2 & MMC_CAP2_FULL_PWR_CYCLE_IN_SUSPEND))) > err = mmc_poweroff_notify(host->card, notify_type); > - else if (mmc_can_sleep(host->card)) > - err = mmc_sleep(host); > + if (mmc_can_sleepawake(host)) { > + memcpy(&host->cached_ios, &host->ios, sizeof(host->cached_ios)); > + mmc_cache_card_ext_csd(host); > + } > + if (mmc_can_sleep(host->card)) > + err = mmc_sleepawake(host, true); > else if (!mmc_host_is_spi(host)) > err = mmc_deselect_cards(host); > > @@ -2117,6 +2194,48 @@ static int _mmc_suspend(struct mmc_host *host, bool is_suspend) > return err; > } > > +static int mmc_partial_init(struct mmc_host *host) { > + int err = 0; > + struct mmc_card *card = host->card; > + > + mmc_set_bus_width(host, host->cached_ios.bus_width); > + mmc_set_timing(host, host->cached_ios.timing); > + if (host->cached_ios.enhanced_strobe) { > + host->ios.enhanced_strobe = true; > + if (host->ops->hs400_enhanced_strobe) > + host->ops->hs400_enhanced_strobe(host, &host->ios); > + } > + mmc_set_clock(host, host->cached_ios.clock); > + mmc_set_bus_mode(host, host->cached_ios.bus_mode); > + > + if (!mmc_card_hs400es(card) && > + (mmc_card_hs200(card) || mmc_card_hs400(card))) { > + err = mmc_execute_tuning(card); > + if (err) { > + pr_err("%s: %s: Tuning failed (%d)\n", > + mmc_hostname(host), __func__, err); > + goto out; > + } > + } > + /* > + * The ext_csd is read to make sure the card did not went through > + * Power-failure during sleep period. > + * A subset of the W/E_P, W/C_P register will be tested. In case > + * these registers values are different from the values that were > + * cached during suspend, we will conclude that a Power-failure occurred > + * and will do full initialization sequence. > + */ > + err = mmc_test_awake_ext_csd(host); > + if (err) { > + pr_debug("%s: %s: fail on ext_csd read (%d)\n", > + mmc_hostname(host), __func__, err); > + goto out; > + } > +out: > + return err; > +} > + > /* > * Suspend callback > */ > @@ -2139,7 +2258,7 @@ static int mmc_suspend(struct mmc_host *host) > */ > static int _mmc_resume(struct mmc_host *host) { > - int err = 0; > + int err = -EINVAL; > > mmc_claim_host(host); > > @@ -2147,7 +2266,19 @@ static int _mmc_resume(struct mmc_host *host) > goto out; > > mmc_power_up(host, host->card->ocr); > - err = mmc_init_card(host, host->card->ocr, host->card); > + > + if (mmc_can_sleepawake(host)) { > + err = mmc_sleepawake(host, false); > + if (!err) > + err = mmc_partial_init(host); > + else > + pr_err("%s: %s: awake failed (%d), fallback to full init\n", > + mmc_hostname(host), __func__, err); > + } > + > + if (err) > + err = mmc_init_card(host, host->card->ocr, host->card); > + > mmc_card_clr_suspended(host->card); > > out: > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 37f9758..ed7f6f7 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -86,6 +86,8 @@ struct mmc_ext_csd { > unsigned int data_tag_unit_size; /* DATA TAG UNIT size */ > unsigned int boot_ro_lock; /* ro lock support */ > bool boot_ro_lockable; > + u8 raw_ext_csd_cmdq; /* 15 */ > + u8 raw_ext_csd_cache_ctrl; /* 33 */ > bool ffu_capable; /* Firmware upgrade support */ > bool cmdq_en; /* Command Queue enabled */ > bool cmdq_support; /* Command Queue supported */ > @@ -96,7 +98,9 @@ struct mmc_ext_csd { > u8 raw_partition_support; /* 160 */ > u8 raw_rpmb_size_mult; /* 168 */ > u8 raw_erased_mem_count; /* 181 */ > + u8 raw_ext_csd_bus_width; /* 183 */ > u8 strobe_support; /* 184 */ > + u8 raw_ext_csd_hs_timing; /* 185 */ > u8 raw_ext_csd_structure; /* 194 */ > u8 raw_card_type; /* 196 */ > u8 raw_driver_strength; /* 197 */ > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index c38072e..a9ddf7a 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -422,6 +422,7 @@ struct mmc_host { > #else > #define MMC_CAP2_CRYPTO 0 > #endif > +#define MMC_CAP2_SLEEP_AWAKE (1 << 29) /* Use Sleep/Awake (CMD5) */ > #define MMC_CAP2_ALT_GPT_TEGRA (1 << 28) /* Host with eMMC that has GPT entry at a non-standard location */ > > int fixed_drv_type; /* fixed driver type for non-removable media */ > @@ -441,6 +442,7 @@ struct mmc_host { > spinlock_t lock; /* lock for claim and bus ops */ > > struct mmc_ios ios; /* current io bus settings */ > + struct mmc_ios cached_ios; > > /* group bitfields together to minimize padding */ > unsigned int use_spi_crc:1; > -- > 2.7.4 >
