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authorJonathan Lemon <bsd@fb.com>2022-03-09 14:34:27 -0800
committerJakub Kicinski <kuba@kernel.org>2022-03-10 20:28:27 -0800
commitc17c4059df2471183a0e0d567677cbd7f0e0a980 (patch)
tree8441c0d8febb1217c983e9ee506a30ba3bb56b95 /drivers/ptp
parent87ed3de674c69f4d998a6e0e1eb04e008ca93f84 (diff)
ptp: ocp: add UPF_NO_THRE_TEST flag for serial ports
The serial port driver attempts to test for correct THRE behavior on startup. However, it does this by disabling interrupts, and then intentionally trying to trigger an interrupt in order to see if the IIR bit is set in the UART. However, in this FPGA design, the UART interrupt is generated through the MSI vector, so when interrupts are re-enabled after the test, the DMAR-IR reports an unhandled IRTE entry, since no irq handler is installed at this point - it is installed after the test. This only happens on the /second/ open of the UART, since on the first open, the x86_vector has installed and activated by the driver probe, and is correctly handled. When the serial port is closed for the first time, this vector is deactivated and removed, leading to this error. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Link: https://lore.kernel.org/r/20220309223427.34745-1-jonathan.lemon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/ptp')
-rw-r--r--drivers/ptp/ptp_ocp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 98b3f01e76c9..653286e01b90 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -1410,7 +1410,7 @@ ptp_ocp_serial_line(struct ptp_ocp *bp, struct ocp_resource *r)
uart.port.mapbase = pci_resource_start(pdev, 0) + r->offset;
uart.port.irq = pci_irq_vector(pdev, r->irq_vec);
uart.port.uartclk = 50000000;
- uart.port.flags = UPF_FIXED_TYPE | UPF_IOREMAP;
+ uart.port.flags = UPF_FIXED_TYPE | UPF_IOREMAP | UPF_NO_THRE_TEST;
uart.port.type = PORT_16550A;
return serial8250_register_8250_port(&uart);