Hello, Since you have reported this problem, I suggest to provide some more details in case you wish to find its root cause. You have not provided any useful information at all! You have just sent the error but everything else is kept in dark... Having that in mind, please elaborate to see what goes wrong. Damien will help you if it caused by any coding error. First of all, provide a full dmesg so that we can see the interesting details. In detail, we need to see the CPU, the SATA host capabilities and the IC used. Moreover, we must see the SSD device you are using as well as the kernel version. Are you using a custom kernel or one of the official releases? Please provide a link to its source in the case of a custom kernel. To track this error, I suggest to increase the kernel buffer and enable CONFIG_ATA_VERBOSE_ERROR. Repeat testing and provide the latest dmesg. Concerning the storage device, does your SSD have power loss protection? Have you tested this configuration with an HDD? If the controller is PCI based, please provide lspci -nnnvvvxxx for all PCI devices run with elevated rights. Also please post hdparm and check your SSD device health. Have you detected any filesystem related corruption? Why do you want to power it down? In regards to the Power Management Unit(PMU), is the system running while the SSD is powered off or does it enter a lower power state as well? For example S3 or S4 speaking ACPI wise. There have been a lot of broken storage devices as well as SATA hosts but no one will be able to help you on this unless you provide additional information. Kind regards.
