mmc: dw_mmc: Remove old card detect infrastructure
The dw_mmc driver had a bunch of code that ran whenever a card was
ejected and inserted. However, this code was old and crufty and
should be removed. Some evidence that it's really not needed:
1. Is is supposed to be legal to use 'cd-gpio' on dw_mmc instead of
using the built-in card detect mechanism. The 'cd-gpio' code
doesn't run any of the crufty old code but yet still works.
2. While looking at this, I realized that my old change (369ac86 mmc:
dw_mmc: don't queue up a card detect at slot startup) actually
castrated the old code a little bit already and nobody noticed.
Specifically "last_detect_state" was left as 0 at bootup. That
means that on the first card removal none of the crufty code ran.
3. I can run "while true; do dd if=/dev/mmcblk1 of=/dev/null; done"
while ejecting and inserting an SD Card and the world doesn't
explode.
If some of the crufty old code is actually needed, we should justify
it and also put it in some place where it will be run even with
"cd-gpio".
Note that in my case I'm using the "cd-gpio" mechanism but for various
reasons the hardware triggers a dw_mmc "card detect" at bootup. That
was actually causing a real bug. The card detect workqueue was
running while the system was trying to enumerate the card. The
"present != slot->last_detect_state" triggered and we were doing all
kinds of crazy stuff and messing up enumeration. The new mechanism of
just asking the core to check the card is much safer and then the
bogus interrupt doesn't hurt.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: alim.akhtar <alim.akhtar@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 545f621..bb46b1b 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -34,7 +34,6 @@
#include <linux/mmc/dw_mmc.h>
#include <linux/bitops.h>
#include <linux/regulator/consumer.h>
-#include <linux/workqueue.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/mmc/slot-gpio.h>
@@ -1959,6 +1958,23 @@
tasklet_schedule(&host->tasklet);
}
+static void dw_mci_handle_cd(struct dw_mci *host)
+{
+ int i;
+
+ for (i = 0; i < host->num_slots; i++) {
+ struct dw_mci_slot *slot = host->slot[i];
+
+ if (!slot)
+ continue;
+
+ if (slot->mmc->ops->card_event)
+ slot->mmc->ops->card_event(slot->mmc);
+ mmc_detect_change(slot->mmc,
+ msecs_to_jiffies(host->pdata->detect_delay_ms));
+ }
+}
+
static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
{
struct dw_mci *host = dev_id;
@@ -2034,7 +2050,7 @@
if (pending & SDMMC_INT_CD) {
mci_writel(host, RINTSTS, SDMMC_INT_CD);
- queue_work(host->card_workqueue, &host->card_work);
+ dw_mci_handle_cd(host);
}
/* Handle SDIO Interrupts */
@@ -2061,88 +2077,6 @@
return IRQ_HANDLED;
}
-static void dw_mci_work_routine_card(struct work_struct *work)
-{
- struct dw_mci *host = container_of(work, struct dw_mci, card_work);
- int i;
-
- for (i = 0; i < host->num_slots; i++) {
- struct dw_mci_slot *slot = host->slot[i];
- struct mmc_host *mmc = slot->mmc;
- struct mmc_request *mrq;
- int present;
-
- present = dw_mci_get_cd(mmc);
- while (present != slot->last_detect_state) {
- dev_dbg(&slot->mmc->class_dev, "card %s\n",
- present ? "inserted" : "removed");
-
- spin_lock_bh(&host->lock);
-
- /* Card change detected */
- slot->last_detect_state = present;
-
- /* Clean up queue if present */
- mrq = slot->mrq;
- if (mrq) {
- if (mrq == host->mrq) {
- host->data = NULL;
- host->cmd = NULL;
-
- switch (host->state) {
- case STATE_IDLE:
- case STATE_WAITING_CMD11_DONE:
- break;
- case STATE_SENDING_CMD11:
- case STATE_SENDING_CMD:
- mrq->cmd->error = -ENOMEDIUM;
- if (!mrq->data)
- break;
- /* fall through */
- case STATE_SENDING_DATA:
- mrq->data->error = -ENOMEDIUM;
- dw_mci_stop_dma(host);
- break;
- case STATE_DATA_BUSY:
- case STATE_DATA_ERROR:
- if (mrq->data->error == -EINPROGRESS)
- mrq->data->error = -ENOMEDIUM;
- /* fall through */
- case STATE_SENDING_STOP:
- if (mrq->stop)
- mrq->stop->error = -ENOMEDIUM;
- break;
- }
-
- dw_mci_request_end(host, mrq);
- } else {
- list_del(&slot->queue_node);
- mrq->cmd->error = -ENOMEDIUM;
- if (mrq->data)
- mrq->data->error = -ENOMEDIUM;
- if (mrq->stop)
- mrq->stop->error = -ENOMEDIUM;
-
- spin_unlock(&host->lock);
- mmc_request_done(slot->mmc, mrq);
- spin_lock(&host->lock);
- }
- }
-
- /* Power down slot */
- if (present == 0)
- dw_mci_reset(host);
-
- spin_unlock_bh(&host->lock);
-
- present = dw_mci_get_cd(mmc);
- }
-
- mmc_detect_change(slot->mmc,
- msecs_to_jiffies(host->pdata->detect_delay_ms));
- }
-}
-
#ifdef CONFIG_OF
/* given a slot id, find out the device node representing that slot */
static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
@@ -2294,9 +2228,6 @@
dw_mci_init_debugfs(slot);
#endif
- /* Card initially undetected */
- slot->last_detect_state = 0;
-
return 0;
err_host_allocated:
@@ -2677,17 +2608,10 @@
host->data_offset = DATA_240A_OFFSET;
tasklet_init(&host->tasklet, dw_mci_tasklet_func, (unsigned long)host);
- host->card_workqueue = alloc_workqueue("dw-mci-card",
- WQ_MEM_RECLAIM, 1);
- if (!host->card_workqueue) {
- ret = -ENOMEM;
- goto err_dmaunmap;
- }
- INIT_WORK(&host->card_work, dw_mci_work_routine_card);
ret = devm_request_irq(host->dev, host->irq, dw_mci_interrupt,
host->irq_flags, "dw-mci", host);
if (ret)
- goto err_workqueue;
+ goto err_dmaunmap;
if (host->pdata->num_slots)
host->num_slots = host->pdata->num_slots;
@@ -2723,7 +2647,7 @@
} else {
dev_dbg(host->dev, "attempted to initialize %d slots, "
"but failed on all\n", host->num_slots);
- goto err_workqueue;
+ goto err_dmaunmap;
}
if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO)
@@ -2731,9 +2655,6 @@
return 0;
-err_workqueue:
- destroy_workqueue(host->card_workqueue);
-
err_dmaunmap:
if (host->use_dma && host->dma_ops->exit)
host->dma_ops->exit(host);
@@ -2767,8 +2688,6 @@
mci_writel(host, CLKENA, 0);
mci_writel(host, CLKSRC, 0);
- destroy_workqueue(host->card_workqueue);
-
if (host->use_dma && host->dma_ops->exit)
host->dma_ops->exit(host);