When mmc host controller enters suspend state, the clocks are
disabled, but irqs are not. For some reason the irqchip emits
false interrupts, which causes system lock loop.
Debug log is:
...
sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded 51200000
sunxi-mmc 1c11000.mmc: enabling the clock
sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0
sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000
sunxi-mmc 1c11000.mmc: cmd 6(80000146) arg 3210101 ie 0x0000bbc6 len 0
sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000
sunxi-mmc 1c11000.mmc: cmd 13(8000014d) arg 10000 ie 0x0000bbc6 len 0
sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00000004 idi 00000000
mmc1: new DDR MMC card at address 0001
mmcblk1: mmc1:0001 AGND3R 14.6 GiB
mmcblk1boot0: mmc1:0001 AGND3R partition 1 4.00 MiB
mmcblk1boot1: mmc1:0001 AGND3R partition 2 4.00 MiB
sunxi-mmc 1c11000.mmc: cmd 18(80003352) arg 0 ie 0x0000fbc2 len 409
sunxi-mmc 1c11000.mmc: irq: rq (ptrval) mi 00004000 idi 00000002
mmcblk1: p1
sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000
sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000
sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000
sunxi-mmc 1c11000.mmc: irq: rq (null) mi 00000000 idi 00000000
and so on...
This issue apears on eMMC cards, routed on MMC2 slot. The patch is
tested with A20-OLinuXino-MICRO/LIME/LIME2 boards.
Fixes: 9a8e1e8cc2c0 ("mmc: sunxi: Add runtime_pm support")
Signed-off-by: Stefan Mavrodiev <stefan@xxxxxxxxxx>
---
Changes in v2:
- Add comment why disable_irq() is necessary
---
drivers/mmc/host/sunxi-mmc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index e747259..8e7f3e3 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -1446,6 +1446,7 @@ static int sunxi_mmc_runtime_resume(struct device *dev)
sunxi_mmc_init_host(host);
sunxi_mmc_set_bus_width(host, mmc->ios.bus_width);
sunxi_mmc_set_clk(host, &mmc->ios);
+ enable_irq(host->irq);
return 0;
}
@@ -1455,6 +1456,12 @@ static int sunxi_mmc_runtime_suspend(struct device *dev)
struct mmc_host *mmc = dev_get_drvdata(dev);
struct sunxi_mmc_host *host = mmc_priv(mmc);
+ /*
+ * When clocks are off, it's possible receiving
+ * fake interrupts, which will stall the system.
+ * Disabling the irq will prevent this.
+ */
+ disable_irq(host->irq);
sunxi_mmc_reset_host(host);
sunxi_mmc_disable(host);
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
