[PATCH 3/4] mmci: sync DATAEND irq with dma|pio transfer done
Linus Walleij
linus.walleij at stericsson.com
Tue Jun 28 03:57:40 EDT 2011
From: Ulf Hansson <ulf.hansson at stericsson.com>
The end of a dma|pio data transfer is synced with the
DATAEND irq. This will prevent the mmci driver from ending
the request before the dma|pio job is completely done.
For dma we use DMA_PREP_INTERRUPT to register a callback
function which is called when dma driver is done with job.
To also make sure we prevent hanging forever, waiting for
DATAEND irq or a dma|pio transfer to be done, we setup a timer
when either a DATAEND or dma|pio job is done. Once both
conditions have occured, the timer is cancelled and the data
transfer is completed.
If a timeout occurs, the data transfer is terminated in a
controlled manner and EAGAIN is returned to the framework.
A timeout value of 50 ms has been found to work well for
our usecases.
Signed-off-by: Ulf Hansson <ulf.hansson at stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
drivers/mmc/host/mmci.c | 211 +++++++++++++++++++++++++++--------------------
drivers/mmc/host/mmci.h | 7 ++-
2 files changed, 126 insertions(+), 92 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index c73d054..93dcd2a 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -37,6 +37,7 @@
#include "mmci.h"
#define DRIVER_NAME "mmci-pl18x"
+#define DATAEND_TIMEOUT_MS 50
static unsigned int fmax = 515633;
@@ -209,6 +210,67 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
}
+static void
+mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
+{
+ void __iomem *base = host->base;
+
+ dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
+ cmd->opcode, cmd->arg, cmd->flags);
+
+ if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
+ writel(0, base + MMCICOMMAND);
+ udelay(1);
+ }
+
+ c |= cmd->opcode | MCI_CPSM_ENABLE;
+ if (cmd->flags & MMC_RSP_PRESENT) {
+ if (cmd->flags & MMC_RSP_136)
+ c |= MCI_CPSM_LONGRSP;
+ c |= MCI_CPSM_RESPONSE;
+ }
+ if (/*interrupt*/0)
+ c |= MCI_CPSM_INTERRUPT;
+
+ host->cmd = cmd;
+
+ writel(cmd->arg, base + MMCIARGUMENT);
+ writel(c, base + MMCICOMMAND);
+}
+
+static void mmci_complete_data_xfer(struct mmci_host *host)
+{
+ struct mmc_data *data = host->data;
+
+ if (((host->size == 0) && host->dataend) || data->error) {
+
+ /*
+ * The data transfer is done and then there is no need for the
+ * a delayed work any more, thus remove it.
+ */
+ host->dataend_timeout_active = false;
+ __cancel_delayed_work(&host->dataend_timeout);
+
+ mmci_stop_data(host);
+
+ if (!data->error)
+ data->bytes_xfered = data->blksz * data->blocks;
+
+ if (!data->stop)
+ mmci_request_end(host, data->mrq);
+ else
+ mmci_start_command(host, data->stop, 0);
+ } else {
+ /*
+ * Schedule a delayed work to make sure we do not end up
+ * forever waiting for a data transfer to be finished.
+ */
+ host->dataend_timeout_active = true;
+ schedule_delayed_work(&host->dataend_timeout,
+ msecs_to_jiffies(DATAEND_TIMEOUT_MS));
+ }
+}
+
/*
* All the DMA operation mode stuff goes inside this ifdef.
* This assumes that you have a generic DMA device interface,
@@ -306,28 +368,6 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
{
struct dma_chan *chan = host->dma_current;
enum dma_data_direction dir;
- u32 status;
- int i;
-
- /* Wait up to 1ms for the DMA to complete */
- for (i = 0; ; i++) {
- status = readl(host->base + MMCISTATUS);
- if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
- break;
- udelay(10);
- }
-
- /*
- * Check to see whether we still have some data left in the FIFO -
- * this catches DMA controllers which are unable to monitor the
- * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
- * contiguous buffers. On TX, we'll get a FIFO underrun error.
- */
- if (status & MCI_RXDATAAVLBLMASK) {
- dmaengine_terminate_all(chan);
- if (!data->error)
- data->error = -EIO;
- }
if (data->flags & MMC_DATA_WRITE) {
dir = DMA_TO_DEVICE;
@@ -336,21 +376,31 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
}
dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+ host->dma_current = NULL;
+}
- /*
- * Use of DMA with scatter-gather is impossible.
- * Give up with DMA and switch back to PIO mode.
- */
- if (status & MCI_RXDATAAVLBLMASK) {
- dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
- mmci_dma_release(host);
- }
+static void mmci_dma_callback(void *arg)
+{
+ unsigned long flags;
+ struct mmci_host *host = arg;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ mmci_dma_unmap(host, host->data);
+
+ /* Mark that the entire data is transferred. */
+ host->size = 0;
+
+ mmci_complete_data_xfer(host);
+
+ spin_unlock_irqrestore(&host->lock, flags);
}
static void mmci_dma_data_error(struct mmci_host *host)
{
dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
dmaengine_terminate_all(host->dma_current);
+ host->dma_current = NULL;
}
static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
@@ -370,8 +420,6 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
struct dma_async_tx_descriptor *desc;
int nr_sg;
- host->dma_current = NULL;
-
if (data->flags & MMC_DATA_READ) {
conf.direction = DMA_FROM_DEVICE;
chan = host->dma_rx_channel;
@@ -395,10 +443,15 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
dmaengine_slave_config(chan, &conf);
desc = device->device_prep_slave_sg(chan, data->sg, nr_sg,
- conf.direction, DMA_CTRL_ACK);
+ conf.direction,
+ DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
if (!desc)
goto unmap_exit;
+ /* Setup dma callback function. */
+ desc->callback = mmci_dma_callback;
+ desc->callback_param = host;
+
/* Okay, go for it. */
host->dma_current = chan;
@@ -413,13 +466,6 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
/* Trigger the DMA transfer */
writel(datactrl, host->base + MMCIDATACTRL);
- /*
- * Let the MMCI say when the data is ended and it's time
- * to fire next DMA request. When that happens, MMCI will
- * call mmci_data_end()
- */
- writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
- host->base + MMCIMASK0);
return 0;
unmap_exit:
@@ -451,6 +497,27 @@ static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datac
}
#endif
+static void mmci_dataend_timeout(struct work_struct *work)
+{
+ unsigned long flags;
+ struct mmci_host *host =
+ container_of(work, struct mmci_host, dataend_timeout.work);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (host->dataend_timeout_active) {
+ dev_err(mmc_dev(host->mmc), "datatransfer timeout!\n");
+
+ if (dma_inprogress(host))
+ mmci_dma_data_error(host);
+
+ host->data->error = -EAGAIN;
+ mmci_complete_data_xfer(host);
+ }
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
struct variant_data *variant = host->variant;
@@ -464,6 +531,7 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
host->data = data;
host->size = data->blksz * data->blocks;
+ host->dataend = false;
data->bytes_xfered = 0;
clks = (unsigned long long)data->timeout_ns * host->cclk;
@@ -520,39 +588,10 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
datactrl |= MCI_ST_DPSM_SDIOEN;
writel(datactrl, base + MMCIDATACTRL);
- writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
mmci_set_mask1(host, irqmask);
}
static void
-mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
-{
- void __iomem *base = host->base;
-
- dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
- cmd->opcode, cmd->arg, cmd->flags);
-
- if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
- writel(0, base + MMCICOMMAND);
- udelay(1);
- }
-
- c |= cmd->opcode | MCI_CPSM_ENABLE;
- if (cmd->flags & MMC_RSP_PRESENT) {
- if (cmd->flags & MMC_RSP_136)
- c |= MCI_CPSM_LONGRSP;
- c |= MCI_CPSM_RESPONSE;
- }
- if (/*interrupt*/0)
- c |= MCI_CPSM_INTERRUPT;
-
- host->cmd = cmd;
-
- writel(cmd->arg, base + MMCIARGUMENT);
- writel(c, base + MMCICOMMAND);
-}
-
-static void
mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
unsigned int status)
{
@@ -599,21 +638,11 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
if (status & MCI_DATABLOCKEND)
dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
- if (status & MCI_DATAEND || data->error) {
- if (dma_inprogress(host))
- mmci_dma_unmap(host, data);
- mmci_stop_data(host);
-
- if (!data->error)
- /* The error clause is handled above, success! */
- data->bytes_xfered = data->blksz * data->blocks;
+ if (status & MCI_DATAEND)
+ host->dataend = true;
- if (!data->stop) {
- mmci_request_end(host, data->mrq);
- } else {
- mmci_start_command(host, data->stop, 0);
- }
- }
+ if (host->dataend || data->error)
+ mmci_complete_data_xfer(host);
}
static void
@@ -636,8 +665,11 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
}
if (!cmd->data || cmd->error) {
- if (host->data)
+ if (host->data) {
+ if (dma_inprogress(host))
+ mmci_dma_data_error(host);
mmci_stop_data(host);
+ }
mmci_request_end(host, cmd->mrq);
} else if (!(cmd->data->flags & MMC_DATA_READ)) {
mmci_start_data(host, cmd->data);
@@ -793,15 +825,10 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
if (status & MCI_RXACTIVE && host->size < variant->fifohalfsize)
mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);
- /*
- * If we run out of data, disable the data IRQs; this
- * prevents a race where the FIFO becomes empty before
- * the chip itself has disabled the data path, and
- * stops us racing with our data end IRQ.
- */
+ /* If we run out of data, disable the data IRQs. */
if (host->size == 0) {
mmci_set_mask1(host, 0);
- writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
+ mmci_complete_data_xfer(host);
}
return IRQ_HANDLED;
@@ -1200,6 +1227,7 @@ static int __devinit mmci_probe(struct amba_device *dev,
dev->irq[0], dev->irq[1]);
mmci_dma_setup(host);
+ INIT_DELAYED_WORK(&host->dataend_timeout, mmci_dataend_timeout);
mmc_add_host(mmc);
@@ -1247,6 +1275,7 @@ static int __devexit mmci_remove(struct amba_device *dev)
writel(0, host->base + MMCIDATACTRL);
mmci_dma_release(host);
+ cancel_delayed_work(&host->dataend_timeout);
free_irq(dev->irq[0], host);
if (!host->singleirq)
free_irq(dev->irq[1], host);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 2164e8c..79156a0 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -153,7 +153,7 @@
#define MCI_IRQENABLE \
(MCI_CMDCRCFAILMASK|MCI_DATACRCFAILMASK|MCI_CMDTIMEOUTMASK| \
MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK| \
- MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_STARTBITERRMASK)
+ MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_STARTBITERRMASK|MCI_DATAENDMASK)
/* These interrupts are directed to IRQ1 when two IRQ lines are available */
#define MCI_IRQ1MASK \
@@ -198,6 +198,11 @@ struct mmci_host {
unsigned int size;
struct regulator *vcc;
+ /* sync of DATAEND irq */
+ bool dataend;
+ bool dataend_timeout_active;
+ struct delayed_work dataend_timeout;
+
#ifdef CONFIG_DMA_ENGINE
/* DMA stuff */
struct dma_chan *dma_current;
--
1.7.3.2
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