Currently i.MX53 boards with the imx-drm display driver active
fail an intensive suspend to ram / resume test.
After around 5 - 50 cycles it is no longer possible to resume
the board.
The culprit is the imx-drm driver which does not stop DMA
before suspending. Removing the driver "fixes" the problem.
This patch provides a minimal suspend / resume implementation
enabling the intensive test to work (500 cycles ok).
I am only sending this as RFC for the moment since I don't
really know the hardware or driver code well enough to be
sure this is the "right" way of doing it.
Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
---
drivers/staging/imx-drm/ipu-v3/ipu-common.c | 47 +++++++++++++++++++++++++++
drivers/staging/imx-drm/ipu-v3/ipu-prv.h | 1 +
2 files changed, 48 insertions(+)
diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-common.c b/drivers/staging/imx-drm/ipu-v3/ipu-common.c
index 97ca692..484a90a 100644
--- a/drivers/staging/imx-drm/ipu-v3/ipu-common.c
+++ b/drivers/staging/imx-drm/ipu-v3/ipu-common.c
@@ -692,6 +692,8 @@ int ipu_idmac_enable_channel(struct ipuv3_channel *channel)
val |= idma_mask(channel->num);
ipu_idmac_write(ipu, val, IDMAC_CHA_EN(channel->num));
+ channel->enabled = true;
+
spin_unlock_irqrestore(&ipu->lock, flags);
return 0;
@@ -750,6 +752,8 @@ int ipu_idmac_disable_channel(struct ipuv3_channel *channel)
val &= ~idma_mask(channel->num);
ipu_cm_write(ipu, val, IPU_CHA_DB_MODE_SEL(channel->num));
+ channel->enabled = false;
+
spin_unlock_irqrestore(&ipu->lock, flags);
return 0;
@@ -1245,10 +1249,53 @@ static int ipu_remove(struct platform_device *pdev)
return 0;
}
+#ifdef CONFIG_PM_SLEEP
+
+static int ipu_suspend(struct device *dev)
+{
+ struct ipu_soc *ipu = dev_get_drvdata(dev);
+ struct ipuv3_channel *channel;
+ int i;
+
+ channel = ipu->channel;
+ for (i = 0; i < ARRAY_SIZE(ipu->channel); i++, channel++) {
+ channel->suspended = false;
+ if (channel->enabled) {
+ if (ipu_idmac_wait_busy(channel, 50))
+ dev_warn(dev,
+ "%s: Timeout channel %d idle\n",
+ __func__, i);
+ ipu_idmac_disable_channel(channel);
+ channel->suspended = true;
+ }
+ }
+ return 0;
+}
+
+static int ipu_resume(struct device *dev)
+{
+ struct ipu_soc *ipu = dev_get_drvdata(dev);
+ struct ipuv3_channel *channel;
+ int i;
+
+ channel = ipu->channel;
+ for (i = 0; i < ARRAY_SIZE(ipu->channel); i++, channel++) {
+ if (channel->suspended) {
+ ipu_idmac_enable_channel(channel);
+ channel->suspended = false;
+ }
+ }
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(ipu_pm_ops, ipu_suspend, ipu_resume);
+
static struct platform_driver imx_ipu_driver = {
.driver = {
.name = "imx-ipuv3",
.of_match_table = imx_ipu_dt_ids,
+ .pm = &ipu_pm_ops,
},
.probe = ipu_probe,
.remove = ipu_remove,
diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-prv.h b/drivers/staging/imx-drm/ipu-v3/ipu-prv.h
index 4df0050..233749a 100644
--- a/drivers/staging/imx-drm/ipu-v3/ipu-prv.h
+++ b/drivers/staging/imx-drm/ipu-v3/ipu-prv.h
@@ -144,6 +144,7 @@ struct ipuv3_channel {
bool enabled;
bool busy;
+ bool suspended;
struct ipu_soc *ipu;
};
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