Hello Heikki, I contact you regarding the 8250_dw driver. My setup is an Asus T100TA (baytrail) + kernel 3.14. The UART controller is ACPI enumerated (ID is 80860F0A). (UART_CAP_AFE capable) This uart is used to communicate with a BCM4324 bluetooth chip (HCI H4 over uart). However we have many bluetooth instabilities. These instabilities are due to the 'hardware error' HCI code sent by the BCM chip. This error means that the BCM received an invalid H4 packet header or an invalid sized packet => serial sync issue. Moreover, Increasing the baudrate increases the hardware error frequency. This problem seems due to the DMA usage. Indeed, when I disable the DMA manually in 8250_dw.c (up->dma = NULL), problem does not occur anymore, all baudrates are stable. Do you think a specific 8250 DMA configuration could apply for the byt case ? How/Where can I debug to know if the 8250 DMA works as expected ? Thanks & Regards, Loic Poulain --------------------------------------------------------------------- Intel Corporation SAS (French simplified joint stock company) Registered headquarters: "Les Montalets"- 2, rue de Paris, 92196 Meudon Cedex, France Registration Number: 302 456 199 R.C.S. NANTERRE Capital: 4,572,000 Euros This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
