Re: SD card reader only works after a suspend/resume

On Thu, Sep 06, 2018 at 12:33:39PM +0200, Jakob Alvermark wrote:
> Hi,
> 
> 
> I discovered this by chance.
> 
> The SD card reader in my laptop has never worked, but now I noticed it 
> does after suspending and resuming.
> 
> The controller is probed and attached on boot:
> 
> sdhci_acpi1: <Intel Bay Trail/Braswell SDXC Controller> iomem 
> 0x90a00000-0x90a00fff irq 47 on acpi0
> 
> But nothing happens if I put a card in. Unless I suspend and resume:
> 
> mmc1: <MMC/SD bus> on sdhci_acpi1
> mmcsd0: 32GB <SDHC SL32G 8.0 SN 19CD02C0 MFG 11/2014 by 3 SD> at mmc1 
> 50.0MHz/4bit/65535-block
> 
> Then I can remove and replug cards and it seems to work just fine.

I believe that making SD card insertion/removal with the integrated
SDHCI controlers of newer Intel SoCs work out-of-the-box requires
support for ACPI GPE interrupts and ACPI GPIO events respectively to
be added to FreeBSD. Otherwise insertion/removal interrutps/events
aren't reported and polling the card present state doesn't generally
work as a workaround with these controllers either, unfortunately.
I'm not aware of anyone working on the former, though.

Polling the card present state happens to work one time after SDHCI
initialization with these controllers which is why a card will be
attached when inserted as part of a suspend/resume cycle (resume of
mmc(4) had some bugs until some months ago, which probably explains
why that procedure hasn't worked as a workaround for you in the past).
Inserting the card before boot, unloading/loading sdhci_acpi.ko or
triggering detach/attach of sdhci_acpi(4) via devctl(8) should allow
to attach a card, too.

Marius