On Monday, May 6, 2019 10:36:22 AM CEST Rafael J. Wysocki wrote:
On Thu, May 2, 2019 at 6:58 AM Vinod Koul vkoul@kernel.org wrote:
On 01-05-19, 07:53, Pierre-Louis Bossart wrote:
Standards such as the MIPI DisCo for SoundWire 1.0 specification assume the _ADR field is 64 bits.
_ADR is defined as an "Integer" represented as 64 bits since ACPI 2.0 released in 2002. The low levels already use _ADR as 64 bits, e.g. in struct acpi_device_info.
This patch bumps the representation used for sysfs to 64 bits. To avoid any compatibility/ABI issues, the printf format is only extended to 16 characters when the actual _ADR value exceeds the 32 bit maximum.
Example with a SoundWire device, the results show the complete vendorID and linkID which were omitted before:
Before: $ more /sys/bus/acpi/devices/device:38/adr 0x5d070000 After: $ more /sys/bus/acpi/devices/device:38/adr 0x000010025d070000
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
v2: only use 64 bits when required to avoid compatibility issues (feedback from Vinod and Rafael)
drivers/acpi/device_sysfs.c | 6 ++++-- include/acpi/acpi_bus.h | 2 +- 2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/device_sysfs.c b/drivers/acpi/device_sysfs.c index 8940054d6250..7dda0ee05cd1 100644 --- a/drivers/acpi/device_sysfs.c +++ b/drivers/acpi/device_sysfs.c @@ -428,8 +428,10 @@ static ssize_t acpi_device_adr_show(struct device *dev, { struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "0x%08x\n",(unsigned int)(acpi_dev->pnp.bus_address));
if (acpi_dev->pnp.bus_address > 0xFFFFFFFF)Would prefer to use U32_MAX instead of 0xFFFFFFFF
I would.
I have made that change manually and applied the patch.
Thanks!