From: Haibo Chen <haibo.chen@xxxxxxx>
During suspend/resume, need to access usdhc register, so need
to enable IPG clock to avoid bus error.
Find this issue when a card slot do not insert a card, so when
system suspend, sdhci_esdhc_runtime_resume() will not be called
before sdhci_esdhc_suspend(), so will meet system hung or bus err
once access usdhc register.
Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
---
The first thing I do is try to merge the sdhci_esdhc_suspend() into
current sdhci_esdhc_runtime_suspend(), but find some obstacles:
1, sdhci_esdhc_imx_hwinit() is called in original sdhci_esdhc_resume(),
it will clear the DLL config, which after remove to sdhci_esdhc_runtime_resume,
will finally impact the DDR50 timing.
2, if merge, everytime after sdhci_esdhc_runtime_resume, will do re-tuning,
this is unnecessary for the normal runtime PM case without power lost.
3, the CD gpio wakeup. Seems strange to enable the CD gpio wakeup in
sdhci_esdhc_runtime_suspend().
So, finally I drop this merge method, and directly add change in the original
sdhci_esdhc_suspend()/sdhci_esdhc_resume().
---
drivers/mmc/host/sdhci-esdhc-imx.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index eebf94604a7f..4cf42a028bb9 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -1836,6 +1836,8 @@ static int sdhci_esdhc_suspend(struct device *dev)
struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
int ret;
+ pm_runtime_get_sync(dev);
+
if (host->mmc->caps2 & MMC_CAP2_CQE) {
ret = cqhci_suspend(host->mmc);
if (ret)
@@ -1855,6 +1857,8 @@ static int sdhci_esdhc_suspend(struct device *dev)
if (ret)
return ret;
+ pm_runtime_force_suspend(dev);
+
ret = pinctrl_pm_select_sleep_state(dev);
if (ret)
return ret;
@@ -1873,6 +1877,8 @@ static int sdhci_esdhc_resume(struct device *dev)
if (ret)
return ret;
+ pm_runtime_force_resume(dev);
+
/* re-initialize hw state in case it's lost in low power mode */
sdhci_esdhc_imx_hwinit(host);
@@ -1886,6 +1892,8 @@ static int sdhci_esdhc_resume(struct device *dev)
if (!ret)
ret = mmc_gpio_set_cd_wake(host->mmc, false);
+ pm_runtime_put_autosuspend(dev);
+
return ret;
}
#endif
--
2.34.1
