cat /sys/kernel/debug/mmc0/regs will hang up the system since
it's in runtime suspended state, so the genpd and biu_clk is
off. This patch fixes this problem by calling pm_runtime_get_sync
to wake it up before reading the registers.
Fixes: e9ed8835e990 ("mmc: dw_mmc: add runtime PM callback")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
drivers/mmc/host/dw_mmc.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 0aa3997..e38dcf4 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -165,6 +165,8 @@ static int dw_mci_regs_show(struct seq_file *s, void *v)
{
struct dw_mci *host = s->private;
+ pm_runtime_get_sync(host->dev);
+
seq_printf(s, "STATUS:\t0x%08x\n", mci_readl(host, STATUS));
seq_printf(s, "RINTSTS:\t0x%08x\n", mci_readl(host, RINTSTS));
seq_printf(s, "CMD:\t0x%08x\n", mci_readl(host, CMD));
@@ -172,6 +174,8 @@ static int dw_mci_regs_show(struct seq_file *s, void *v)
seq_printf(s, "INTMASK:\t0x%08x\n", mci_readl(host, INTMASK));
seq_printf(s, "CLKENA:\t0x%08x\n", mci_readl(host, CLKENA));
+ pm_runtime_put_autosuspend(host->dev);
+
return 0;
}
--
1.9.1