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authorShawn Lin <shawn.lin@rock-chips.com>2018-02-23 11:47:25 +0300
committerUlf Hansson <ulf.hansson@linaro.org>2018-02-27 17:12:36 +0300
commit5b43df8b4c1a7f0c3fbf793c9566068e6b1e570c (patch)
tree9d8a72f1db810fe6705d3597fe9999bda4ed1ad9 /drivers/mmc
parent0d84b9e5631d923744767dc6608672df906dd092 (diff)
downloadlinux-5b43df8b4c1a7f0c3fbf793c9566068e6b1e570c.tar.xz
mmc: dw_mmc: Avoid accessing registers in runtime suspended state
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@vger.kernel.org> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/dw_mmc.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index a850f8d7d4b5..d9b4acefed31 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;
}