On 02/23/2018 05:47 PM, Shawn Lin wrote:
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
Best Regards, Jaehoon Chung
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;
}