diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0224-bcm2835-sdhost-Precalc-divisors-and-overclocks.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0224-bcm2835-sdhost-Precalc-divisors-and-overclocks.patch | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0224-bcm2835-sdhost-Precalc-divisors-and-overclocks.patch b/target/linux/brcm2708/patches-4.4/0224-bcm2835-sdhost-Precalc-divisors-and-overclocks.patch new file mode 100644 index 0000000000..14c2e8c861 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0224-bcm2835-sdhost-Precalc-divisors-and-overclocks.patch @@ -0,0 +1,270 @@ +From 20260462773366a5734e5268dae0a4c179a21a2d Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Thu, 31 Mar 2016 15:44:53 +0100 +Subject: [PATCH 224/232] bcm2835-sdhost: Precalc divisors and overclocks + +Recalculating the clock divisors when the core clock changes is wasteful +and makes it harder to manage the overclock settings. Instead, +precalculate them and only report significant changes. + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + drivers/mmc/host/bcm2835-sdhost.c | 152 ++++++++++++++++++++++---------------- + 1 file changed, 88 insertions(+), 64 deletions(-) + +--- a/drivers/mmc/host/bcm2835-sdhost.c ++++ b/drivers/mmc/host/bcm2835-sdhost.c +@@ -154,12 +154,15 @@ struct bcm2835_host { + u32 pio_timeout; /* In jiffies */ + + int clock; /* Current clock speed */ ++ int clocks[2]; + + bool slow_card; /* Force 11-bit divisor */ + + unsigned int max_clk; /* Max src clock freq */ +- unsigned int min_clk; /* Min src clock freq */ +- unsigned int cur_clk; /* Current src clock freq */ ++ unsigned int src_clks[2]; /* Min/max src clock freqs */ ++ unsigned int cur_clk_idx; /* Index of current clock */ ++ unsigned int next_clk_idx; /* Next clock index */ ++ unsigned int cdivs[2]; + + struct tasklet_struct finish_tasklet; /* Tasklet structures */ + +@@ -213,7 +216,7 @@ struct bcm2835_host { + u32 delay_after_stop; /* minimum time between stop and subsequent data transfer */ + u32 delay_after_this_stop; /* minimum time between this stop and subsequent data transfer */ + u32 overclock_50; /* frequency to use when 50MHz is requested (in MHz) */ +- u32 overclock; /* Current frequency if overclocked, else zero */ ++ u32 prev_overclock_50; + u32 pio_limit; /* Maximum block count for PIO (0 = always DMA) */ + + u32 sectors; /* Cached card size in sectors */ +@@ -1509,10 +1512,35 @@ static irqreturn_t bcm2835_sdhost_irq(in + return result; + } + ++static void bcm2835_sdhost_select_clock(struct bcm2835_host *host, int idx) ++{ ++ unsigned int clock = host->clocks[idx]; ++ unsigned int cdiv = host->cdivs[idx]; ++ ++ host->mmc->actual_clock = clock; ++ host->ns_per_fifo_word = (1000000000/clock) * ++ ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32); ++ ++ host->cdiv = cdiv; ++ bcm2835_sdhost_write(host, host->cdiv, SDCDIV); ++ ++ /* Set the timeout to 500ms */ ++ bcm2835_sdhost_write(host, clock/2, SDTOUT); ++ ++ host->cur_clk_idx = host->next_clk_idx = idx; ++ ++ if (host->debug) ++ pr_info("%s: clock=%d -> src_clk=%d, cdiv=%x (actual %d)\n", ++ mmc_hostname(host->mmc), host->clock, ++ host->src_clks[idx], host->cdiv, ++ host->mmc->actual_clock); ++} ++ + void bcm2835_sdhost_set_clock(struct bcm2835_host *host) + { + int div = 0; /* Initialized for compiler warning */ + unsigned int clock = host->clock; ++ int clk_idx; + + if (host->debug) + pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock); +@@ -1553,53 +1581,45 @@ void bcm2835_sdhost_set_clock(struct bcm + return; + } + +- div = host->cur_clk / clock; +- if (div < 2) +- div = 2; +- if ((host->cur_clk / div) > clock) +- div++; +- div -= 2; +- +- if (div > SDCDIV_MAX_CDIV) +- div = SDCDIV_MAX_CDIV; +- +- clock = host->cur_clk / (div + 2); +- host->mmc->actual_clock = clock; +- +- /* Calibrate some delays */ +- +- host->ns_per_fifo_word = (1000000000/clock) * +- ((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32); ++ /* Calculate the clock divisors */ ++ for (clk_idx = 0; clk_idx <= host->variable_clock; clk_idx++) ++ { ++ unsigned int cur_clk = host->src_clks[clk_idx]; ++ unsigned int actual_clock; + +- if (clock > host->clock) { +- /* Save the closest value, to make it easier +- to reduce in the event of error */ +- host->overclock_50 = (clock/MHZ); +- +- if (clock != host->overclock) { +- pr_warn("%s: overclocking to %dHz\n", +- mmc_hostname(host->mmc), clock); +- host->overclock = clock; ++ div = cur_clk / clock; ++ if (div < 2) ++ div = 2; ++ if ((cur_clk / div) > clock) ++ div++; ++ div -= 2; ++ ++ if (div > SDCDIV_MAX_CDIV) ++ div = SDCDIV_MAX_CDIV; ++ actual_clock = cur_clk / (div + 2); ++ ++ host->cdivs[clk_idx] = div; ++ host->clocks[clk_idx] = actual_clock; ++ ++ if (host->overclock_50 != host->prev_overclock_50) { ++ const char *clk_name = ""; ++ if (host->variable_clock) ++ clk_name = clk_idx ? " (turbo)" : " (normal)"; ++ if (actual_clock > host->clock) ++ pr_info("%s: overclocking to %dHz%s\n", ++ mmc_hostname(host->mmc), ++ actual_clock, clk_name); ++ else if ((host->overclock_50 < 50) && (clk_idx == 0)) ++ pr_info("%s: cancelling overclock%s\n", ++ mmc_hostname(host->mmc), ++ host->variable_clock ? "s" : ""); + } + } +- else if (host->overclock) +- { +- host->overclock = 0; +- if (clock == 50 * MHZ) +- pr_warn("%s: cancelling overclock\n", +- mmc_hostname(host->mmc)); +- } + +- host->cdiv = div; +- bcm2835_sdhost_write(host, host->cdiv, SDCDIV); ++ if (host->clock == 50*MHZ) ++ host->prev_overclock_50 = host->overclock_50; + +- /* Set the timeout to 500ms */ +- bcm2835_sdhost_write(host, host->mmc->actual_clock/2, SDTOUT); +- +- if (host->debug) +- pr_info("%s: clock=%d -> cur_clk=%d, cdiv=%x (actual clock %d)\n", +- mmc_hostname(host->mmc), host->clock, +- host->cur_clk, host->cdiv, host->mmc->actual_clock); ++ bcm2835_sdhost_select_clock(host, host->cur_clk_idx); + } + + static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq) +@@ -1657,6 +1677,9 @@ static void bcm2835_sdhost_request(struc + + spin_lock_irqsave(&host->lock, flags); + ++ if (host->next_clk_idx != host->cur_clk_idx) ++ bcm2835_sdhost_select_clock(host, host->next_clk_idx); ++ + WARN_ON(host->mrq != NULL); + host->mrq = mrq; + +@@ -1719,11 +1742,7 @@ static int bcm2835_sdhost_cpufreq_callba + return NOTIFY_BAD; + break; + case CPUFREQ_POSTCHANGE: +- if (freq->new > freq->old) +- host->cur_clk = host->max_clk; +- else +- host->cur_clk = host->min_clk; +- bcm2835_sdhost_set_clock(host); ++ host->next_clk_idx = (freq->new > freq->old); + up(&host->cpufreq_semaphore); + break; + default: +@@ -1763,8 +1782,11 @@ static void bcm2835_sdhost_set_ios(struc + ios->clock, ios->power_mode, ios->bus_width, + ios->timing, ios->signal_voltage, ios->drv_type); + +- if (ios->clock && !host->cur_clk) +- host->cur_clk = get_core_clock(RPI_FIRMWARE_GET_CLOCK_RATE); ++ if (ios->clock && (host->cur_clk_idx == -1)) { ++ unsigned int cur_clk = ++ get_core_clock(RPI_FIRMWARE_GET_CLOCK_RATE); ++ host->cur_clk_idx = (cur_clk == host->src_clks[0]) ? 0 : 1; ++ } + + spin_lock_irqsave(&host->lock, flags); + +@@ -1854,11 +1876,12 @@ static void bcm2835_sdhost_tasklet_finis + + /* Drop the overclock after any data corruption, or after any + error overclocked */ +- if (host->overclock) { ++ if (host->clock > 50*MHZ) { + if ((mrq->cmd && mrq->cmd->error) || + (mrq->data && mrq->data->error) || + (mrq->stop && mrq->stop->error)) { +- host->overclock_50--; ++ host->overclock_50 = (host->clock/MHZ) - 1; ++ + pr_warn("%s: reducing overclock due to errors\n", + mmc_hostname(host->mmc)); + bcm2835_sdhost_set_clock(host); +@@ -2022,7 +2045,7 @@ static int bcm2835_sdhost_probe(struct p + struct bcm2835_host *host; + struct mmc_host *mmc; + const __be32 *addr; +- unsigned int max_clk; ++ unsigned int max_clk, min_clk; + int ret; + + pr_debug("bcm2835_sdhost_probe\n"); +@@ -2128,12 +2151,8 @@ static int bcm2835_sdhost_probe(struct p + else + mmc->caps |= MMC_CAP_4_BIT_DATA; + +- ret = bcm2835_sdhost_add_host(host); +- if (ret) +- goto err; +- + /* Query the core clock frequencies */ +- host->min_clk = get_core_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE); ++ min_clk = get_core_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE); + max_clk = get_core_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE); + if (max_clk != host->max_clk) { + pr_warn("%s: Expected max clock %d, found %d\n", +@@ -2141,19 +2160,24 @@ static int bcm2835_sdhost_probe(struct p + host->max_clk = max_clk; + } + +- if (host->min_clk != host->max_clk) { ++ host->src_clks[0] = min_clk; ++ host->cur_clk_idx = -1; ++ if (max_clk != min_clk) { ++ host->src_clks[1] = max_clk; + host->cpufreq_nb.notifier_call = + bcm2835_sdhost_cpufreq_callback; + sema_init(&host->cpufreq_semaphore, 1); + cpufreq_register_notifier(&host->cpufreq_nb, + CPUFREQ_TRANSITION_NOTIFIER); + host->variable_clock = 1; +- host->cur_clk = 0; /* Get this later */ + } else { + host->variable_clock = 0; +- host->cur_clk = host->max_clk; + } + ++ ret = bcm2835_sdhost_add_host(host); ++ if (ret) ++ goto err; ++ + platform_set_drvdata(pdev, host); + + pr_debug("bcm2835_sdhost_probe -> OK\n"); |