Re: [PATCH v2 0/2] rtsx_usb: fix tray-reader false card detect and autosuspend

[Ulf Hansson]

On Mon, Jul 6, 2026 at 5:40 PM Sean Rhodes <sean@starlabs.systems> wrote:
>
> This series fixes the empty-tray detect loop seen on a Realtek RTS5129
> USB SD reader, while also avoiding USB register accesses from the USB
> runtime autosuspend callback.
>
> Compared with the previous RFC, this no longer qualifies media by issuing
> SD/MMC commands from ->get_cd().  The rtsx_usb_sdmmc child still reports
> the raw card-detect state initially, then lets the normal MMC rescan path
> probe the media.  If an initialization command times out before a card is
> attached, the SD child suppresses the raw SD_CD signal until the tray/card
> detect line drops again.
>
> The parent rtsx_usb change removes USB I/O from runtime autosuspend and
> keeps only the existing Memory Stick autosuspend deferral based on cached
> card-status bits.  Raw SD_CD is not used as a parent autosuspend blocker,
> because this reader can assert it for an empty tray.
>
> Runtime-tested on a StarLite Mk V with Realtek RTS5129 (0bda:0129), using
> these changes as a matched rtsx_usb/rtsx_usb_sdmmc/rtsx_usb_ms module set
> on Linux 7.0.0-27-generic.
>
> Device enumeration:
>   Bus 001 Device 003: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
>   /:  Bus 001.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/12p, 480M
>       |__ Port 004: Dev 003, If 0, Class=Vendor Specific Class, Driver=rtsx_usb, 480M
>
> Card inserted:
>   mmc0: new UHS-I speed SDR50 SDXC card at address 544c
>   mmcblk0: mmc0:544c LX2TB 1.82 TiB
>    mmcblk0: p1
>
> Deep S3 with the card inserted:
>   PM: suspend entry (deep)
>   ACPI: PM: Waking up from system sleep state S3
>   PM: suspend exit
>
> After resume, the card remained visible:
>   NAME         SIZE TYPE FSTYPE MOUNTPOINTS
>   mmcblk0      1.8T disk
>   `-mmcblk0p1  1.8T part exfat
>
> Empty tray:
>   mmc0: card 544c removed
>   /sys/bus/usb/devices/1-4/power/control=auto
>   /sys/bus/usb/devices/1-4/power/runtime_status=suspended
>   /sys/bus/usb/devices/1-4/power/runtime_usage=0
>
> With the empty tray left inserted for about three minutes, no repeated
> MMC detect attempts, command timeouts, or USB reset churn were observed.
>
> Sean Rhodes (2):
>   misc: rtsx_usb: avoid USB I/O in runtime autosuspend
>   mmc: rtsx_usb_sdmmc: suppress false CD after init timeout
>
>  drivers/misc/cardreader/rtsx_usb.c | 26 ++++++++++++++++++++------
>  drivers/mmc/host/rtsx_usb_sdmmc.c  | 13 ++++++++++++-
>  include/linux/rtsx_usb.h           |  3 +++
>  3 files changed, 35 insertions(+), 7 deletions(-)
>

I decided to queue the series for next to get it thoroughly tested.
Potentially we should also tag these for stable kernels, but let's get
it tested a bit more in next first.

Greg, please let me know if you have any objections that I pick this
via my mmc tree, or please provide your ack.

Kind regards
Uffe