Hi, > From: Rafael J. Wysocki [mailto:rjw@xxxxxxxxxxxxx] > Sent: Wednesday, September 16, 2015 9:57 AM > > On Tuesday, September 15, 2015 02:04:58 PM Viresh Kumar wrote: > > global_lock is defined as an unsigned long and accessing only its lower > > 32 bits from sysfs is incorrect, as we need to consider other 32 bits > > for big endian 64 bit systems. > > > > Fix that by making global_lock an u32 instead. > > > > Cc: <stable@xxxxxxxxxxxxxxx> # v4.1+ > > Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx> > > > > --- > > Its marked just for # v4.1+, because arm64 has the first 64 big-endian > > platform with ACPI. And ACPI support for that is mainlined recently > > only (Arnd Bergmann). > > OK > > So are you aware of any ARM platform implementing the ACPI EC? > > I am not. Moreover, I'm not aware of any plans in that area. > > > Another thing worth noticing is that, global_lock is getting an unsigned > > long long value assigned to it in ec_parse_device() and this is what > > Arnd had to say about that: > > > > "I think that's fine, it does this because the _GLP variable in ACPI is > > defined as an u64. And that's what happens on 32-bit architectures > > anyway." > > > > This patch should go via GregKH, as the second patch has dependency on > > it. > > > > V2->V3: > > - Moved this out in a separate patch, so that it can be backported. > > Lv, can you have a look at this, please? > > > --- > > drivers/acpi/ec_sys.c | 2 +- > > drivers/acpi/internal.h | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/acpi/ec_sys.c b/drivers/acpi/ec_sys.c > > index b4c216bab22b..bea8e425a8de 100644 > > --- a/drivers/acpi/ec_sys.c > > +++ b/drivers/acpi/ec_sys.c > > @@ -128,7 +128,7 @@ static int acpi_ec_add_debugfs(struct acpi_ec *ec, unsigned int ec_device_count) > > if (!debugfs_create_x32("gpe", 0444, dev_dir, (u32 *)&first_ec->gpe)) > > goto error; > > if (!debugfs_create_bool("use_global_lock", 0444, dev_dir, > > - (u32 *)&first_ec->global_lock)) > > + &first_ec->global_lock)) > > goto error; > > > > if (write_support) > > diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h > > index 9e426210c2a8..9db196de003c 100644 > > --- a/drivers/acpi/internal.h > > +++ b/drivers/acpi/internal.h > > @@ -138,7 +138,7 @@ struct acpi_ec { > > unsigned long gpe; > > unsigned long command_addr; > > unsigned long data_addr; > > - unsigned long global_lock; > > + u32 global_lock; > > unsigned long flags; > > unsigned long reference_count; > > struct mutex mutex; > > > If we really want to change, we may change everything here. gpe/command_addr/data_addr/global_lock. And IMO, if we really want to change global_lock, we should make it bool here. Thanks and best regards -Lv > Thanks, > Rafael ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
