On Mon, Aug 03, 2015 at 08:32:33PM +0100, Graeme Gregory wrote:
We better CC Torez and Mark as SPCR is their work.
Well, tbh, the below was mainly intended for LEG-kernel.
For any upstream submissions, if people agree this is the right way to go, we'd be better off merging the sets before resubmission.
/ Leif
On Mon, Aug 03, 2015 at 06:15:56PM +0100, Leif Lindholm wrote:
The first version of SPCR handling code identified the correct device by comparing the address in SPCR with _ADR objects, through walking the namespace.
Instead, use the required _CRS object for this matching, making the functionality more portable.
Signed-off-by: Leif Lindholm leif.lindholm@linaro.org
By my interpretation of the spec, the use of _ADR for this purpose is incorrect. Regardless, this patch makes automatic SPCR console identification work on Juno and FVP.
arch/arm64/kernel/acpi.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index c5c6e49..64129b8 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -313,31 +313,37 @@ static int __init acpi_parse_spcr(struct acpi_table_header *table) static acpi_status acpi_spcr_device_scan(acpi_handle handle, u32 level, void *context, void **retv) {
- unsigned long long adr;
- unsigned long long adr = 0; struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_status status = AE_OK; struct acpi_device *adev;
- struct list_head resource_list;
- struct resource_entry *rentry;
status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &name_buffer); if (ACPI_FAILURE(status)) return status;
- adev = acpi_bus_get_acpi_device(handle);
- if (!adev) {
pr_err("Err locating SPCR device from ACPI handle\n");return AE_OK; /* skip this one */- }
- /*
* does thie APCI entry have an associated Address?
* Read device address from _CRS.
- status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
- if (ACPI_FAILURE(status))
return AE_OK; /* not device we are interested in... */- if (adr == spcr_serial_addr) {
adev = acpi_bus_get_acpi_device(handle);
- INIT_LIST_HEAD(&resource_list);
- if (acpi_dev_get_resources(adev, &resource_list, NULL, NULL) <= 0)
return AE_OK;
if (!adev) {pr_err("Err locating SPCR device from ACPI handle\n");return AE_OK; /* skip this one */}
- list_for_each_entry(rentry, &resource_list, node) {
if (resource_type(rentry->res) == IORESOURCE_MEM)adr = rentry->res->start;- }
- acpi_dev_free_resource_list(&resource_list);
- if (adr == spcr_serial_addr) { acpi_spcr_serial_device = adev;
pr_info("SPCR serial console: %s (0x%llx)\n", -- 2.1.4