The patch titled mmc: omap: lazy clock shutdown has been added to the -mm tree. Its filename is mmc-omap-lazy-clock-shutdown.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mmc: omap: lazy clock shutdown From: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx> MMCA spec says the mmc clock should be kept running for at least 8 cycles after the last RW request. Ensure this with lazy clock disable after a request, or with an explicit delay before switching a slot. Signed-off-by: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx> Cc: Tony Lindgren <tony@xxxxxxxxxxx> Cc: Pierre Ossman <drzeus-list@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/omap.c | 89 ++++++++++++++++++++++++++++++++------ 1 file changed, 75 insertions(+), 14 deletions(-) diff -puN drivers/mmc/host/omap.c~mmc-omap-lazy-clock-shutdown drivers/mmc/host/omap.c --- a/drivers/mmc/host/omap.c~mmc-omap-lazy-clock-shutdown +++ a/drivers/mmc/host/omap.c @@ -161,9 +161,38 @@ struct mmc_omap_host { wait_queue_head_t slot_wq; int nr_slots; + struct timer_list clk_timer; + spinlock_t clk_lock; /* for changing enabled state */ + unsigned int fclk_enabled:1; + struct omap_mmc_platform_data *pdata; }; +void mmc_omap_fclk_offdelay(struct mmc_omap_slot *slot) +{ + unsigned long tick_ns; + + if (slot != NULL && slot->host->fclk_enabled && slot->fclk_freq > 0) { + tick_ns = (1000000000 + slot->fclk_freq - 1) / slot->fclk_freq; + ndelay(8 * tick_ns); + } +} + +void mmc_omap_fclk_enable(struct mmc_omap_host *host, unsigned int enable) +{ + unsigned long flags; + + spin_lock_irqsave(&host->clk_lock, flags); + if (host->fclk_enabled != enable) { + host->fclk_enabled = enable; + if (enable) + clk_enable(host->fclk); + else + clk_disable(host->fclk); + } + spin_unlock_irqrestore(&host->clk_lock, flags); +} + static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed) { struct mmc_omap_host *host = slot->host; @@ -180,32 +209,49 @@ static void mmc_omap_select_slot(struct host->mmc = slot->mmc; spin_unlock_irqrestore(&host->slot_lock, flags); no_claim: - clk_enable(host->fclk); + del_timer(&host->clk_timer); + if (host->current_slot != slot || !claimed) + mmc_omap_fclk_offdelay(host->current_slot); + if (host->current_slot != slot) { + OMAP_MMC_WRITE(host, CON, slot->saved_con & 0xFC00); if (host->pdata->switch_slot != NULL) host->pdata->switch_slot(mmc_dev(slot->mmc), slot->id); host->current_slot = slot; } - /* Doing the dummy read here seems to work around some bug - * at least in OMAP24xx silicon where the command would not - * start after writing the CMD register. Sigh. */ - OMAP_MMC_READ(host, CON); + if (claimed) { + mmc_omap_fclk_enable(host, 1); + + /* Doing the dummy read here seems to work around some bug + * at least in OMAP24xx silicon where the command would not + * start after writing the CMD register. Sigh. */ + OMAP_MMC_READ(host, CON); - OMAP_MMC_WRITE(host, CON, slot->saved_con); + OMAP_MMC_WRITE(host, CON, slot->saved_con); + } else + mmc_omap_fclk_enable(host, 0); } static void mmc_omap_start_request(struct mmc_omap_host *host, struct mmc_request *req); -static void mmc_omap_release_slot(struct mmc_omap_slot *slot) +static void mmc_omap_release_slot(struct mmc_omap_slot *slot, int clk_enabled) { struct mmc_omap_host *host = slot->host; unsigned long flags; int i; BUG_ON(slot == NULL || host->mmc == NULL); - clk_disable(host->fclk); + + if (clk_enabled) + /* Keeps clock running for at least 8 cycles on valid freq */ + mod_timer(&host->clk_timer, jiffies + HZ/10); + else { + del_timer(&host->clk_timer); + mmc_omap_fclk_offdelay(slot); + mmc_omap_fclk_enable(host, 0); + } spin_lock_irqsave(&host->slot_lock, flags); /* Check for any pending requests */ @@ -373,7 +419,7 @@ mmc_omap_xfer_done(struct mmc_omap_host host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, data->mrq); return; } @@ -507,7 +553,7 @@ mmc_omap_cmd_done(struct mmc_omap_host * mmc_omap_abort_xfer(host, host->data); host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, cmd->mrq); } } @@ -538,7 +584,7 @@ static void mmc_omap_abort_command(struc host->mrq = NULL; mmc = host->mmc; - mmc_omap_release_slot(host->current_slot); + mmc_omap_release_slot(host->current_slot, 1); mmc_request_done(mmc, cmd->mrq); } else mmc_omap_cmd_done(host, host->cmd); @@ -576,6 +622,14 @@ mmc_omap_sg_to_buf(struct mmc_omap_host host->buffer_bytes_left = host->total_bytes_left; } +static void +mmc_omap_clk_timer(unsigned long data) +{ + struct mmc_omap_host *host = (struct mmc_omap_host *) data; + + mmc_omap_fclk_enable(host, 0); +} + /* PIO only */ static void mmc_omap_xfer_data(struct mmc_omap_host *host, int write) @@ -1149,14 +1203,16 @@ static void mmc_omap_set_ios(struct mmc_ struct mmc_omap_slot *slot = mmc_priv(mmc); struct mmc_omap_host *host = slot->host; int i, dsor; - - dsor = mmc_omap_calc_divisor(mmc, ios); + int clk_enabled; mmc_omap_select_slot(slot, 0); + dsor = mmc_omap_calc_divisor(mmc, ios); + if (ios->vdd != slot->vdd) slot->vdd = ios->vdd; + clk_enabled = 0; switch (ios->power_mode) { case MMC_POWER_OFF: mmc_omap_set_power(slot, 0, ios->vdd); @@ -1166,6 +1222,8 @@ static void mmc_omap_set_ios(struct mmc_ mmc_omap_set_power(slot, 1, ios->vdd); goto exit; case MMC_POWER_ON: + mmc_omap_fclk_enable(host, 1); + clk_enabled = 1; dsor |= 1 << 11; break; } @@ -1194,7 +1252,7 @@ static void mmc_omap_set_ios(struct mmc_ } exit: - mmc_omap_release_slot(slot); + mmc_omap_release_slot(slot, clk_enabled); } static int mmc_omap_get_ro(struct mmc_host *mmc) @@ -1357,6 +1415,9 @@ static int __init mmc_omap_probe(struct setup_timer(&host->cmd_abort_timer, mmc_omap_cmd_timer, (unsigned long) host); + spin_lock_init(&host->clk_lock); + setup_timer(&host->clk_timer, mmc_omap_clk_timer, (unsigned long) host); + spin_lock_init(&host->dma_lock); setup_timer(&host->dma_timer, mmc_omap_dma_timer, (unsigned long) host); spin_lock_init(&host->slot_lock); _ Patches currently in -mm which might be from jarkko.lavinen@xxxxxxxxx are mmc-omap-introduce-new-multislot-structure-and-change-driver-to-use-it.patch mmc-omap-add-back-cover-switch-support.patch mmc-omap-fix-timeout-calculation-for-mmc-multislot-support.patch mmc-omap-abort-stuck-commands.patch mmc-omap-use-tasklet-instead-of-workqueue-for-cover-switch-notification.patch mmc-omap-move-failing-command-abortion-to-workqueue.patch mmc-omap-lazy-clock-shutdown.patch mmc-omap-start-new-commands-from-work-queue-instead-of-irq.patch mmc-omap-do-not-busy-wait-for-end-of-command-for-ever.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html