Hi Matthias,
Thank you for review. The bug is fixed in the next version of the patchset.
Aleksey Makarov
On 02/23/2016 05:37 PM, Matthias Brugger wrote:
>
>
> On 23/02/16 14:57, Graeme Gregory wrote:
>> On Mon, Feb 22, 2016 at 04:45:17PM +0100, Matthias Brugger wrote:
>>>
>>>
>>> On 22/02/16 14:46, Aleksey Makarov wrote:
>>>> From: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
>>>>
>>>> In order to support selecting earlycon via either ACPI or DT, move
>>>> the decision on whether to attempt ACPI configuration into the
>>>> early_param handling. Then make acpi_boot_table_init() bail out if
>>>> acpi_disabled.
>>>>
>>>> Signed-off-by: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
>>>> ---
>>>> arch/arm64/kernel/acpi.c | 54 ++++++++++++++++++++++++++----------------------
>>>> 1 file changed, 29 insertions(+), 25 deletions(-)
>>>>
>>>> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
>>>> index d1ce8e2..7a944f7 100644
>>>> --- a/arch/arm64/kernel/acpi.c
>>>> +++ b/arch/arm64/kernel/acpi.c
>>>> @@ -44,6 +44,19 @@ EXPORT_SYMBOL(acpi_pci_disabled);
>>>> static bool param_acpi_off __initdata;
>>>> static bool param_acpi_force __initdata;
>>>>
>>>> +static int __init dt_scan_depth1_nodes(unsigned long node,
>>>> + const char *uname, int depth,
>>>> + void *data)
>>>> +{
>>>> + /*
>>>> + * Return 1 as soon as we encounter a node at depth 1 that is
>>>> + * not the /chosen node.
>>>> + */
>>>> + if (depth == 1 && (strcmp(uname, "chosen") != 0))
>>>> + return 1;
>>>> + return 0;
>>>> +}
>>>> +
>>>> static int __init parse_acpi(char *arg)
>>>> {
>>>> if (!arg)
>>>> @@ -57,23 +70,27 @@ static int __init parse_acpi(char *arg)
>>>> else
>>>> return -EINVAL; /* Core will print when we return error */
>
> If argument of parse_acpi is neither "off" nor "force" we return with -EINVAL here. Actually parse_acpi will be only called if we pass "acpi=" as kernel parameter. Therefor we can get rid of "acpi=off" as this is the _new_ standard. IMHO we should introduce "acpi=on" if we really want to change the standard behavior.
>
>>>>
>>>> - return 0;
>>>> -}
>>>> -early_param("acpi", parse_acpi);
>>>> + /*
>>>> + * Enable ACPI instead of device tree unless
>>>> + * - ACPI has been disabled explicitly (acpi=off), or
>>>> + * - the device tree is not empty (it has more than just a /chosen node)
>>>> + * and ACPI has not been force enabled (acpi=force)
>>>> + */
>>>> + if (param_acpi_off ||
>>>> + (!param_acpi_force && of_scan_flat_dt(dt_scan_depth1_nodes, NULL)))
>>>> + return 0;
>
> Or param_acpi_off is true or param_acpi_force is true, the depth of the DT has no influence.
>
>>>>
>>>> -static int __init dt_scan_depth1_nodes(unsigned long node,
>>>> - const char *uname, int depth,
>>>> - void *data)
>>>> -{
>>>> /*
>>>> - * Return 1 as soon as we encounter a node at depth 1 that is
>>>> - * not the /chosen node.
>>>> + * ACPI is disabled at this point. Enable it in order to parse
>>>> + * the ACPI tables and carry out sanity checks
>>>> */
>>>> - if (depth == 1 && (strcmp(uname, "chosen") != 0))
>>>> - return 1;
>>>> + enable_acpi();
>>>> +
>>>
>>> So we only enable ACPI if we pass acpi=force as kernel parameter?
>>> I'm not sure if this is what you wanted to do.
>>>
>>
>> The current preference from ARM64 maintainers was that is both ACPI
>> tables and a DT were presented then DT should take precedence.
>>
>> With no DT provided the code should use ACPI.
>
> From my understanding in this patch that can never happen.
>
> On which version is this set based on?
> I'm looking on v4.5-rc5 ATM.
>
> Regards,
> Matthias
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
