diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0234-bcm2835-sdhost-Reset-the-clock-in-task-context.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0234-bcm2835-sdhost-Reset-the-clock-in-task-context.patch | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0234-bcm2835-sdhost-Reset-the-clock-in-task-context.patch b/target/linux/brcm2708/patches-4.4/0234-bcm2835-sdhost-Reset-the-clock-in-task-context.patch new file mode 100644 index 0000000000..006db3f861 --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0234-bcm2835-sdhost-Reset-the-clock-in-task-context.patch @@ -0,0 +1,107 @@ +From 6a5e76800cf6d16d01b8e186806decc047590e46 Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Mon, 11 Apr 2016 12:50:58 +0100 +Subject: [PATCH 234/304] bcm2835-sdhost: Reset the clock in task context + +Since reprogramming the clock can now involve a round-trip to the +firmware it must not be done at atomic context, and a tasklet +is not a task. + +Signed-off-by: Phil Elwell <phil@raspberrypi.org> +--- + drivers/mmc/host/bcm2835-sdhost.c | 25 ++++++++++++++++++------- + 1 file changed, 18 insertions(+), 7 deletions(-) + +--- a/drivers/mmc/host/bcm2835-sdhost.c ++++ b/drivers/mmc/host/bcm2835-sdhost.c +@@ -185,6 +185,7 @@ struct bcm2835_host { + + unsigned int debug:1; /* Enable debug output */ + unsigned int firmware_sets_cdiv:1; /* Let the firmware manage the clock */ ++ unsigned int reset_clock:1; /* Reset the clock fore the next request */ + + /*DMA part*/ + struct dma_chan *dma_chan_rxtx; /* DMA channel for reads and writes */ +@@ -1505,6 +1506,7 @@ void bcm2835_sdhost_set_clock(struct bcm + { + int div = 0; /* Initialized for compiler warning */ + unsigned int input_clock = clock; ++ unsigned long flags; + + if (host->debug) + pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock); +@@ -1544,13 +1546,17 @@ void bcm2835_sdhost_set_clock(struct bcm + &msg, sizeof(msg)); + + clock = max(msg[1], msg[2]); ++ spin_lock_irqsave(&host->lock, flags); + } else { ++ spin_lock_irqsave(&host->lock, flags); + if (clock < 100000) { + /* Can't stop the clock, but make it as slow as + * possible to show willing + */ + host->cdiv = SDCDIV_MAX_CDIV; + bcm2835_sdhost_write(host, host->cdiv, SDCDIV); ++ mmiowb(); ++ spin_unlock_irqrestore(&host->lock, flags); + return; + } + +@@ -1605,6 +1611,11 @@ void bcm2835_sdhost_set_clock(struct bcm + bcm2835_sdhost_write(host, clock/2, SDTOUT); + + host->mmc->actual_clock = clock; ++ host->clock = input_clock; ++ host->reset_clock = 0; ++ ++ mmiowb(); ++ spin_unlock_irqrestore(&host->lock, flags); + } + + static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq) +@@ -1653,6 +1664,9 @@ static void bcm2835_sdhost_request(struc + (mrq->data->blocks > host->pio_limit)) + bcm2835_sdhost_prepare_dma(host, mrq->data); + ++ if (host->reset_clock) ++ bcm2835_sdhost_set_clock(host, host->clock); ++ + spin_lock_irqsave(&host->lock, flags); + + WARN_ON(host->mrq != NULL); +@@ -1731,14 +1745,12 @@ static void bcm2835_sdhost_set_ios(struc + + bcm2835_sdhost_write(host, host->hcfg, SDHCFG); + +- if (!ios->clock || ios->clock != host->clock) { +- bcm2835_sdhost_set_clock(host, ios->clock); +- host->clock = ios->clock; +- } +- + mmiowb(); + + spin_unlock_irqrestore(&host->lock, flags); ++ ++ if (!ios->clock || ios->clock != host->clock) ++ bcm2835_sdhost_set_clock(host, ios->clock); + } + + static struct mmc_host_ops bcm2835_sdhost_ops = { +@@ -1810,7 +1822,7 @@ static void bcm2835_sdhost_tasklet_finis + host->overclock_50--; + pr_warn("%s: reducing overclock due to errors\n", + mmc_hostname(host->mmc)); +- bcm2835_sdhost_set_clock(host,50*MHZ); ++ host->reset_clock = 1; + mrq->cmd->error = -EILSEQ; + mrq->cmd->retries = 1; + } +@@ -1979,7 +1991,6 @@ static int bcm2835_sdhost_probe(struct p + mmc->ops = &bcm2835_sdhost_ops; + host = mmc_priv(mmc); + host->mmc = mmc; +- host->cmd_quick_poll_retries = 0; + host->pio_timeout = msecs_to_jiffies(500); + host->pio_limit = 1; + host->max_delay = 1; /* Warn if over 1ms */ |