So that we don't need to busy checking the busy state,
but relinguish the CPU and rely on the hareware interrupt
if available.
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Tested-by: Ziyuan Xu <xzy.xu@xxxxxxxxxxxxxx>
---
Changes in v2:
- add tag from Ziyuan Xu
- remove lock for checking event since it's already atomic operation
drivers/mmc/host/dw_mmc.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/mmc/host/dw_mmc.h | 6 ++++++
2 files changed, 57 insertions(+)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 703dedf..f58d878 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -107,6 +107,8 @@ struct idmac_desc {
/* Each descriptor can transfer up to 4KB of data in chained mode */
#define DW_MCI_DESC_DATA_LENGTH 0x1000
+DECLARE_WAIT_QUEUE_HEAD(unbusy_waiter);
+
#if defined(CONFIG_DEBUG_FS)
static int dw_mci_req_show(struct seq_file *s, void *v)
{
@@ -231,9 +233,35 @@ static bool dw_mci_ctrl_reset(struct dw_mci *host, u32 reset)
return true;
}
+static inline int dw_mci_wait_hw_unbusy(struct dw_mci *host,
+ unsigned long timeout)
+{
+ unsigned long irqflags;
+ int err;
+
+ set_bit(EVENT_UNBUSY_COMPLETE, &host->pending_events);
+ err = host->drv_data->prepare_hw_unbusy(host, true);
+ if (err)
+ return err;
+
+ wait_event_interruptible_timeout(unbusy_waiter,
+ !test_bit(EVENT_UNBUSY_COMPLETE,
+ &host->pending_events),
+ timeout);
+
+ if (test_and_clear_bit(EVENT_UNBUSY_COMPLETE,
+ &host->pending_events)) {
+ dev_err(host->dev, "Busy; trying anyway\n");
+ host->drv_data->prepare_hw_unbusy(host, false);
+ }
+
+ return 0;
+}
+
static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags)
{
u32 status;
+ int err;
/*
* Databook says that before issuing a new data transfer command
@@ -245,6 +273,14 @@ static void dw_mci_wait_while_busy(struct dw_mci *host, u32 cmd_flags)
*/
if ((cmd_flags & SDMMC_CMD_PRV_DAT_WAIT) &&
!(cmd_flags & SDMMC_CMD_VOLT_SWITCH)) {
+ /* Resort to hw unbusy interrupt first */
+ if (host->drv_data->prepare_hw_unbusy) {
+ err = dw_mci_wait_hw_unbusy(host,
+ jiffies + msecs_to_jiffies(500));
+ if (!err)
+ return;
+ }
+
if (readl_poll_timeout_atomic(host->regs + SDMMC_STATUS,
status,
!(status & SDMMC_STATUS_BUSY),
@@ -2734,6 +2770,14 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
dw_mci_handle_cd(host);
}
+ /* Check hardware unbusy interrupt */
+ if (host->hw_unbusy_int != -EINVAL &&
+ pending & BIT(host->hw_unbusy_int)) {
+ mci_writel(host, RINTSTS, BIT(host->hw_unbusy_int));
+ clear_bit(EVENT_UNBUSY_COMPLETE, &host->pending_events);
+ wake_up_interruptible(&unbusy_waiter);
+ }
+
if (pending & SDMMC_INT_SDIO(slot->sdio_id)) {
mci_writel(host, RINTSTS,
SDMMC_INT_SDIO(slot->sdio_id));
@@ -3249,6 +3293,8 @@ int dw_mci_probe(struct dw_mci *host)
reset_control_deassert(host->pdata->rstc);
}
+ host->hw_unbusy_int = -EINVAL;
+
if (drv_data && drv_data->init) {
ret = drv_data->init(host);
if (ret) {
@@ -3360,6 +3406,11 @@ int dw_mci_probe(struct dw_mci *host)
mci_writel(host, INTMASK, SDMMC_INT_CMD_DONE | SDMMC_INT_DATA_OVER |
SDMMC_INT_TXDR | SDMMC_INT_RXDR |
DW_MCI_ERROR_FLAGS);
+
+ if (host->hw_unbusy_int != -EINVAL)
+ mci_writel(host, INTMASK,
+ mci_readl(host, INTMASK) | BIT(host->hw_unbusy_int));
+
/* Enable mci interrupt */
mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 46e9f8e..fb4c173 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -33,6 +33,7 @@ enum dw_mci_state {
enum {
EVENT_CMD_COMPLETE = 0,
+ EVENT_UNBUSY_COMPLETE,
EVENT_XFER_COMPLETE,
EVENT_DATA_COMPLETE,
EVENT_DATA_ERROR,
@@ -124,6 +125,7 @@ struct dw_mci_dma_slave {
* @irq_flags: The flags to be passed to request_irq.
* @irq: The irq value to be passed to request_irq.
* @sdio_id0: Number of slot0 in the SDIO interrupt registers.
+ * @hw_unbusy_int: Number of unbusy interrupt in the interrupt registers.
* @cmd11_timer: Timer for SD3.0 voltage switch over scheme.
* @cto_timer: Timer for broken command transfer over scheme.
* @dto_timer: Timer for broken data transfer over scheme.
@@ -230,6 +232,7 @@ struct dw_mci {
int irq;
int sdio_id0;
+ int hw_unbusy_int;
struct timer_list cmd11_timer;
struct timer_list cto_timer;
@@ -551,6 +554,8 @@ struct dw_mci_slot {
* @set_ios: handle bus specific extensions.
* @parse_dt: parse implementation specific device tree properties.
* @execute_tuning: implementation specific tuning procedure.
+ * @prepare_hw_unbusy: implementation specific procedure for
+ * controlling hw unbusy interrupt.
*
* Provide controller implementation specific extensions. The usage of this
* data structure is fully optional and usage of each member in this structure
@@ -565,6 +570,7 @@ struct dw_mci_drv_data {
int (*execute_tuning)(struct dw_mci_slot *slot, u32 opcode);
int (*prepare_hs400_tuning)(struct dw_mci *host,
struct mmc_ios *ios);
+ int (*prepare_hw_unbusy)(struct dw_mci *host, bool enable);
int (*switch_voltage)(struct mmc_host *mmc,
struct mmc_ios *ios);
};
--
1.9.1
