diff options
Diffstat (limited to 'drivers/acpi/spcr.c')
| -rw-r--r-- | drivers/acpi/spcr.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index b8019c4c1d38..2b5d0fac81f0 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -16,6 +16,26 @@ #include <linux/kernel.h> #include <linux/serial_core.h> +/* + * Some Qualcomm Datacenter Technologies SoCs have a defective UART BUSY bit. + * Detect them by examining the OEM fields in the SPCR header, similiar to PCI + * quirk detection in pci_mcfg.c. + */ +static bool qdf2400_erratum_44_present(struct acpi_table_header *h) +{ + if (memcmp(h->oem_id, "QCOM ", ACPI_OEM_ID_SIZE)) + return false; + + if (!memcmp(h->oem_table_id, "QDF2432 ", ACPI_OEM_TABLE_ID_SIZE)) + return true; + + if (!memcmp(h->oem_table_id, "QDF2400 ", ACPI_OEM_TABLE_ID_SIZE) && + h->oem_revision == 0) + return true; + + return false; +} + /** * parse_spcr() - parse ACPI SPCR table and add preferred console * @@ -93,6 +113,9 @@ int __init parse_spcr(bool earlycon) goto done; } + if (qdf2400_erratum_44_present(&table->header)) + uart = "qdf2400_e44"; + snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, table->serial_port.address, baud_rate); |