| Message ID | 1499117589-4829-3-git-send-email-lho@apm.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Rafael Wysocki |
| Headers | show |
On Mon, Jul 3, 2017 at 11:33 PM, Loc Ho <lho@apm.com> wrote: > APM X-Gene verion 1 and 2 have an 8250 UART with its register > aligned to 32-bit. In addition, the latest released BIOS > encodes the access field as 8-bit access instead 32-bit access. > This causes no console with ACPI boot as the console > will not match X-Gene UART port due to the lack of mmio32 > option. > > Signed-off-by: Loc Ho <lho@apm.com> Greg, Aleksey, any objections? If not, I'll route this through the ACPI tree. > --- > drivers/acpi/spcr.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c > index 2905063..4ac3e06 100644 > --- a/drivers/acpi/spcr.c > +++ b/drivers/acpi/spcr.c > @@ -36,6 +36,26 @@ static bool qdf2400_erratum_44_present(struct acpi_table_header *h) > return false; > } > > +/* > + * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its > + * register aligned to 32-bit. In addition, the BIOS also encoded the > + * access width to be 8 bits. This function detects this errata condition. > + */ > +static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) > +{ > + if (tb->interface_type != ACPI_DBG2_16550_COMPATIBLE) > + return false; > + > + if (memcmp(tb->header.oem_id, "APMC0D", ACPI_OEM_ID_SIZE)) > + return false; > + > + if (!memcmp(tb->header.oem_table_id, "XGENESPC", > + ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 0) > + return true; > + > + return false; > +} > + > /** > * parse_spcr() - parse ACPI SPCR table and add preferred console > * > @@ -129,6 +149,8 @@ int __init parse_spcr(bool earlycon) > > if (qdf2400_erratum_44_present(&table->header)) > uart = "qdf2400_e44"; > + if (xgene_8250_erratum_present(table)) > + iotype = "mmio32"; > > snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, > table->serial_port.address, baud_rate); > -- > 1.8.3.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 2905063..4ac3e06 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -36,6 +36,26 @@ static bool qdf2400_erratum_44_present(struct acpi_table_header *h) return false; } +/* + * APM X-Gene v1 and v2 UART hardware is an 16550 like device but has its + * register aligned to 32-bit. In addition, the BIOS also encoded the + * access width to be 8 bits. This function detects this errata condition. + */ +static bool xgene_8250_erratum_present(struct acpi_table_spcr *tb) +{ + if (tb->interface_type != ACPI_DBG2_16550_COMPATIBLE) + return false; + + if (memcmp(tb->header.oem_id, "APMC0D", ACPI_OEM_ID_SIZE)) + return false; + + if (!memcmp(tb->header.oem_table_id, "XGENESPC", + ACPI_OEM_TABLE_ID_SIZE) && tb->header.oem_revision == 0) + return true; + + return false; +} + /** * parse_spcr() - parse ACPI SPCR table and add preferred console * @@ -129,6 +149,8 @@ int __init parse_spcr(bool earlycon) if (qdf2400_erratum_44_present(&table->header)) uart = "qdf2400_e44"; + if (xgene_8250_erratum_present(table)) + iotype = "mmio32"; snprintf(opts, sizeof(opts), "%s,%s,0x%llx,%d", uart, iotype, table->serial_port.address, baud_rate);
APM X-Gene verion 1 and 2 have an 8250 UART with its register aligned to 32-bit. In addition, the latest released BIOS encodes the access field as 8-bit access instead 32-bit access. This causes no console with ACPI boot as the console will not match X-Gene UART port due to the lack of mmio32 option. Signed-off-by: Loc Ho <lho@apm.com> --- drivers/acpi/spcr.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)