On Thursday 10 September 2015 01:01 PM, Jisheng Zhang wrote:
Hi Vaibhav,
On Thu, 10 Sep 2015 12:40:48 +0530
Vaibhav Hiremath <vaibhav.hiremath@xxxxxxxxxx> wrote:
Hi,
During my testing of SDHCI-PXAV3 driver on Marvell's pxa1928
based platform, I observed that runtime PM suspend/resume is having
issues with card insertion and removal.
Let me try to explain it using execution sequence -
During boot:
MMC SD card gets detected as expected.
[ 2.431012] mmc1: new high speed SDHC card at address 1234
[ 2.437235] mmcblk1: mmc1:1234 SA04G 3.63 GiB
[ 2.444841] mmcblk1: p1
Now after coming to the linux prompt, if card removal event occurs
then the call sequence is -
sdhci_irq() -->
-> sdhci_thread_irq(): host->thread_isr - 0x80
-> sdhci_card_event()
-> mmc_detect_change()
--> _mmc_detect_change()
---> mmc_sd_detect()
mmc_sd_remove()
mmc_remove_card()
mmc_bus_remove()
mmc_power_off()
mmc_set_initial_state()
sdhci_set_ios()
...
sdhci_pxav3_runtime_suspend()
sdhci_runtime_suspend_host()
Till here everything looks perfect :) (if I got it right)
Now on card insertion again, the expectation is, runtime resume should
get called as part of interrupt trigger from the SDHCI controller on
card insertion.
AFAIK, card insertion => wakeup irq, this irq doesn't come from SDHCI
controller itself because SDHCI controller is runtime suspended, clk gated
or power gated. So the wakeup irq should come from other always on components.
Take Marvell berlin SoC as an example:
there's gpio for sdcard detect, card insertion => trigger cd gpio interrupt
=>resume sdhci host etc.
Not always.
In my case SDHCI controller is generating card insert and remove
event/interrupts. Just to add here, I am not configuring any pins
to GPIO mode. My pin configuration for card-detect is in MMC_CD mode.
The card insertion and removal interrupt is mapped to SDHCI interrupt
line, which is interrupt number 12 in my case.
# cat /proc/interrupts
CPU0
11: 55 GIC 105 Level mmc0
12: 220 GIC 101 Level mmc1
If your changes work, the I guess your SDHCI host are not clk gated or
power gated during runtime suspended.
This is what I suspected initially, but it doesn't look that way.
Without this change, if I just disable/remove
pm_runtime_put_autosuspend(&pdev->dev);
then also it works for me. What it tells me that, if I disable
runtime_pm then it works.
I can cross-check register values to make sure that it is really turned
off. Let me do that as well.
Thanks,
Vaibhav
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