[PATCH 09/13] mmc: bcm2835: switch locking to mutex
From: Gerd Hoffmann
Date: Thu Jan 26 2017 - 18:40:34 EST
so we can sleep now in most bcm2835 code.
especially bcm2835_finish_command can always sleep.
FIXME: timeout timer seems to run in irq context.
FIXME: tasklet seems to run in irq context too.
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
---
drivers/mmc/host/bcm2835.c | 74 +++++++++++++++++++---------------------------
1 file changed, 31 insertions(+), 43 deletions(-)
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 2bea4e0..5c588d9 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -136,6 +136,7 @@
struct bcm2835_host {
spinlock_t lock;
+ struct mutex mutex;
void __iomem *ioaddr;
u32 phys_addr;
@@ -278,8 +279,7 @@ static void bcm2835_reset(struct mmc_host *mmc)
bcm2835_reset_internal(host);
}
-static void bcm2835_finish_command(struct bcm2835_host *host,
- unsigned long *irq_flags);
+static void bcm2835_finish_command(struct bcm2835_host *host);
static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
{
@@ -325,9 +325,8 @@ static void bcm2835_dma_complete(void *param)
{
struct bcm2835_host *host = param;
struct mmc_data *data = host->data;
- unsigned long flags;
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
if (host->dma_chan) {
dma_unmap_sg(host->dma_chan->device->dev,
@@ -357,7 +356,7 @@ static void bcm2835_dma_complete(void *param)
bcm2835_finish_data(host);
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
}
static void bcm2835_transfer_block_pio(struct bcm2835_host *host,
@@ -744,7 +743,7 @@ static void bcm2835_transfer_complete(struct bcm2835_host *host)
if (bcm2835_send_command(host, host->mrq->stop)) {
/* No busy, so poll for completion */
if (!host->use_busy)
- bcm2835_finish_command(host, NULL);
+ bcm2835_finish_command(host);
}
} else {
bcm2835_wait_transfer_complete(host);
@@ -782,11 +781,7 @@ static void bcm2835_finish_data(struct bcm2835_host *host)
}
}
-/* If irq_flags is valid, the caller is in a thread context and is
- * allowed to sleep
- */
-static void bcm2835_finish_command(struct bcm2835_host *host,
- unsigned long *irq_flags)
+static void bcm2835_finish_command(struct bcm2835_host *host)
{
struct device *dev = &host->pdev->dev;
struct mmc_command *cmd = host->cmd;
@@ -837,18 +832,10 @@ static void bcm2835_finish_command(struct bcm2835_host *host,
if (!retries) {
unsigned long wait_max;
- if (!irq_flags) {
- /* Schedule the work */
- schedule_work(&host->cmd_wait_wq);
- return;
- }
-
/* Wait max 100 ms */
wait_max = jiffies + msecs_to_jiffies(100);
while (time_before(jiffies, wait_max)) {
- spin_unlock_irqrestore(&host->lock, *irq_flags);
usleep_range(1, 10);
- spin_lock_irqsave(&host->lock, *irq_flags);
sdcmd = readl(host->ioaddr + SDCMD);
if (!(sdcmd & SDCMD_NEW_FLAG) ||
(sdcmd & SDCMD_FAIL_FLAG))
@@ -913,7 +900,7 @@ static void bcm2835_finish_command(struct bcm2835_host *host,
bcm2835_start_dma(host);
if (!host->use_busy)
- bcm2835_finish_command(host, NULL);
+ bcm2835_finish_command(host);
}
} else if (cmd == host->mrq->stop) {
/* Finished CMD12 */
@@ -932,9 +919,8 @@ static void bcm2835_timeout(unsigned long data)
{
struct bcm2835_host *host = (struct bcm2835_host *)data;
struct device *dev = &host->pdev->dev;
- unsigned long flags;
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
if (host->mrq) {
dev_err(dev, "timeout waiting for hardware interrupt.\n");
@@ -953,7 +939,8 @@ static void bcm2835_timeout(unsigned long data)
tasklet_schedule(&host->finish_tasklet);
}
}
- spin_unlock_irqrestore(&host->lock, flags);
+
+ mutex_unlock(&host->mutex);
}
static bool bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
@@ -1011,7 +998,7 @@ static void bcm2835_busy_irq(struct bcm2835_host *host)
}
host->use_busy = false;
- bcm2835_finish_command(host, NULL);
+ bcm2835_finish_command(host);
}
static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
@@ -1137,6 +1124,10 @@ static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
host->irq_busy = false;
host->irq_data = false;
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ mutex_lock(&host->mutex);
+
if (block)
bcm2835_block_irq(host);
if (busy)
@@ -1144,7 +1135,7 @@ static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
if (data)
bcm2835_data_threaded_irq(host);
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
return IRQ_HANDLED;
}
@@ -1215,7 +1206,6 @@ static void bcm2835_request(struct mmc_host *mmc,
{
struct bcm2835_host *host = mmc_priv(mmc);
struct device *dev = &host->pdev->dev;
- unsigned long flags;
u32 edm, fsm;
/* Reset the error statuses in case this is a retry */
@@ -1240,7 +1230,7 @@ static void bcm2835_request(struct mmc_host *mmc,
(mrq->data->blocks > host->pio_limit))
bcm2835_prepare_dma(host, mrq->data);
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
WARN_ON(host->mrq);
host->mrq = mrq;
@@ -1256,7 +1246,7 @@ static void bcm2835_request(struct mmc_host *mmc,
bcm2835_dumpregs(host);
mrq->cmd->error = -EILSEQ;
tasklet_schedule(&host->finish_tasklet);
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
return;
}
@@ -1264,7 +1254,7 @@ static void bcm2835_request(struct mmc_host *mmc,
if (host->use_sbc) {
if (bcm2835_send_command(host, mrq->sbc)) {
if (!host->use_busy)
- bcm2835_finish_command(host, &flags);
+ bcm2835_finish_command(host);
}
} else if (bcm2835_send_command(host, mrq->cmd)) {
if (host->data && host->dma_desc) {
@@ -1273,18 +1263,17 @@ static void bcm2835_request(struct mmc_host *mmc,
}
if (!host->use_busy)
- bcm2835_finish_command(host, &flags);
+ bcm2835_finish_command(host);
}
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
}
static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct bcm2835_host *host = mmc_priv(mmc);
- unsigned long flags;
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
if (!ios->clock || ios->clock != host->clock) {
bcm2835_set_clock(host, ios->clock);
@@ -1303,7 +1292,7 @@ static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
writel(host->hcfg, host->ioaddr + SDHCFG);
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
}
static struct mmc_host_ops bcm2835_ops = {
@@ -1315,39 +1304,37 @@ static void bcm2835_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
static void bcm2835_cmd_wait_work(struct work_struct *work)
{
struct bcm2835_host *host;
- unsigned long flags;
host = container_of(work, struct bcm2835_host, cmd_wait_wq);
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
/* If this tasklet gets rescheduled while running, it will
* be run again afterwards but without any active request.
*/
if (!host->mrq) {
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
return;
}
- bcm2835_finish_command(host, &flags);
+ bcm2835_finish_command(host);
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
}
static void bcm2835_tasklet_finish(unsigned long param)
{
struct bcm2835_host *host = (struct bcm2835_host *)param;
- unsigned long flags;
struct mmc_request *mrq;
struct dma_chan *terminate_chan = NULL;
- spin_lock_irqsave(&host->lock, flags);
+ mutex_lock(&host->mutex);
/* If this tasklet gets rescheduled while running, it will
* be run again afterwards but without any active request.
*/
if (!host->mrq) {
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
return;
}
@@ -1363,7 +1350,7 @@ static void bcm2835_tasklet_finish(unsigned long param)
terminate_chan = host->dma_chan;
host->dma_chan = NULL;
- spin_unlock_irqrestore(&host->lock, flags);
+ mutex_unlock(&host->mutex);
if (terminate_chan) {
int err = dmaengine_terminate_all(terminate_chan);
@@ -1400,6 +1387,7 @@ int bcm2835_add_host(struct bcm2835_host *host)
MMC_CAP_CMD23;
spin_lock_init(&host->lock);
+ mutex_init(&host->mutex);
if (IS_ERR_OR_NULL(host->dma_chan_tx) ||
IS_ERR_OR_NULL(host->dma_chan_rx)) {
--
1.8.3.1