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On an HPE ProLiant Compute DL110 Gen12 or HPE ProLiant Compute EL140, when accessing the UART1 interface (ttyS2) that is electrically connected to the GNSS module in the system design, certain Linux distributions may exhibit unstable UART behavior, including:Kernel call trace in the logirq 45: nobody cared warningscat /dev/ttyS2 returning no output at startupGNSS ToD messages not appearing at startupIn these cases, UART1 becomes inaccessible until the system is rebooted. If the UART starts successfully, it does not stop mid‑operation. This behavior is caused by DesignWare 8250 UART BUSY‑handling limitations under constant RX pressure and the legacy ACPI UART definition currently used. A complete solution requires both OS driver updates and the UEFI update to v1.30.When using GNSS services (gpsd, ts2phc, gpsmon, ToD readers), the following may occur:· Kernel call trace such as:irq 45: nobody cared (try booting with "irqpoll")dw-apb-uart INTC10EE:00: failed to request DMAGNSS NMEA data not displaying (cat /dev/ttyS2 empty at startup)gpsd / ts2phc / gpsmon hanging or failing to startRecovery only after:System rebootAC power-cycleFailures typically occur when running:cat /dev/ttyS2stty -F /dev/ttyS2 38400 ...gpsd, gpsmon, ts2phc accessing the UARTGNSS‑based time synchronization may intermittently failLoss of ToD data at startup may affect dependent applicationsReboot may be required to restore UART accessNo data corruption or permanent loss expectedIntel identified that the DW8250 UART used for GNSS(INTC10EE) asserts BUSY under constant RX pressure. With the current driver behavior with ACPI table declaring the interface as uart-16550-compatible, the Linux driver performs standard register writes that conflict with hardware BUSY behavior, causing the following:Interrupt storms (IIR_NO_INT)BUSY_DETECT not handled correctlyDMA request failuresKernel call trace followed by IRQ disable (IRQ 45)Intel provided a 7 patch upstream series addressing locking, BUSY handling, interrupt behavior, and DMA interactions. To enable the new driver behavior, the ACPI table must be updated to remove the uart-16550-compatible flag. Therefore, both firmware and driver changes are required for long-term resolution. A firmware change is already included in UEFI v1.30.Below is the kernel stack trace:
Any HPE ProLiant Compute DL110 Gen12 or HPE ProLiant Compute EL140 Gen12 with GNSS module installed and running Red Hat Enterprise Linux 9.6, Red Hat Enterprise Linux 10, SUSE Linux Enterprise Server 16, or Ubuntu 24.04 LTS.
Perform the following:Ensure the OS includes the Intel DW8250 patch series, obtained from Red Hat (or other Linux distribution).AndUpdate the HPE ProLiant Compute DL110 Gen12 or HPE ProLiant Compute EL140 Gen12 to System ROM version 1.30 (or later).Linux kernel patch:Kernel patches are merged into mainline kernel 7.0.0-rc5https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/drivers/tty?h=v7.0-rc5These patches also queued to stable branches (5.10 onwards -https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/commit/?id=3c4d025e91b018feefe32a544c0eeed9c9b596dbWind River will be included in the upcoming WRCP25.09.x and WRCP26.03.x patch content.Red Hat will wait for the Kernel 7.0 release and backport as required into Red Hat Enterprise Linux 9.6.To download the HPE ProLiant Compute DL110 Gen12 or HPE ProLiant Compute EL140 Gen12 system ROM version 1.30 (or later), perform the following steps:Click the following link:Hewlett Packard Enterprise Support CenterEnter a product name (e.g.,"ProLiant Compute DL110 Gen12") in "Find Products and Downloads" search field.When the product appears, click the "DRIVERS AND SOFTWARE" tab near the top of the page.Click the Product name.Click the "BIOS" tab.Locate and select the applicable version of the System ROM (or later).Click the Download button.Document VersionRelease DateDetails2April 22, 2026Include the Linux kernel –accepted patch version and align with some Linux distributions.1February 27, 2026Original Document Release.
Operating Systems Affected:Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, SUSE Linux Enterprise Server 16, Ubuntu 24.04 LTS
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