On Fri, 10 Feb 2023 20:41:19 +0100
Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Hi,
>
> On 2/10/23 05:48, Orlando Chamberlain wrote:
> > Read gmux version in one go as 32 bits on both indexed and classic
> > gmux's.
> >
> > Classic gmux's used to read the version as
> >
> > major = inb(base + 0x4);
> > minor = inb(base + 0x5);
> > release = inb(base + 0x6);
> >
> > but this can instead be done the same way as indexed gmux's with
> > gmux_read32(), so the same version reading code is used for classic
> > and indexed gmux's (as well as mmio gmux's that will be added to
> > this driver).
> >
> > Signed-off-by: Orlando Chamberlain <orlandoch.dev@xxxxxxxxx>
> > ---
> > drivers/platform/x86/apple-gmux.c | 14 ++++++--------
> > include/linux/apple-gmux.h | 6 +-----
> > 2 files changed, 7 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/platform/x86/apple-gmux.c
> > b/drivers/platform/x86/apple-gmux.c index
> > e8cb084cb81f..67628104f31a 100644 ---
> > a/drivers/platform/x86/apple-gmux.c +++
> > b/drivers/platform/x86/apple-gmux.c @@ -580,15 +580,13 @@ static
> > int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
> > if (indexed) { mutex_init(&gmux_data->index_lock);
> > gmux_data->indexed = true;
> > - version = gmux_read32(gmux_data,
> > GMUX_PORT_VERSION_MAJOR);
> > - ver_major = (version >> 24) & 0xff;
> > - ver_minor = (version >> 16) & 0xff;
> > - ver_release = (version >> 8) & 0xff;
> > - } else {
> > - ver_major = gmux_read8(gmux_data,
> > GMUX_PORT_VERSION_MAJOR);
> > - ver_minor = gmux_read8(gmux_data,
> > GMUX_PORT_VERSION_MINOR);
> > - ver_release = gmux_read8(gmux_data,
> > GMUX_PORT_VERSION_RELEASE); }
> > +
> > + version = gmux_read32(gmux_data, GMUX_PORT_VERSION_MAJOR);
> > + ver_major = (version >> 24) & 0xff;
> > + ver_minor = (version >> 16) & 0xff;
> > + ver_release = (version >> 8) & 0xff;
> > +
> > pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major,
> > ver_minor, ver_release, (gmux_data->indexed ? "indexed" :
> > "classic"));
>
> The problem with this is that there is nothing (no known register)
> at address base + 7 and now you are reading from address base + 7
> here where before the code was not, we have no idea how the hw
> will respond to this. This should be pretty innocent but still ...
That makes sense, hopefully someone will be able to test it.
>
> > diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h
> > index 1f68b49bcd68..eb2caee04abd 100644
> > --- a/include/linux/apple-gmux.h
> > +++ b/include/linux/apple-gmux.h
> > @@ -67,7 +67,6 @@ static inline bool apple_gmux_is_indexed(unsigned
> > long iostart) */
> > static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool
> > *indexed_ret) {
> > - u8 ver_major, ver_minor, ver_release;
> > struct device *dev = NULL;
> > struct acpi_device *adev;
> > struct resource *res;
> > @@ -95,10 +94,7 @@ static inline bool apple_gmux_detect(struct
> > pnp_dev *pnp_dev, bool *indexed_ret)
> > * Invalid version information may indicate either that
> > the gmux
> > * device isn't present or that it's a new one that uses
> > indexed io. */
> > - ver_major = inb(res->start + GMUX_PORT_VERSION_MAJOR);
> > - ver_minor = inb(res->start + GMUX_PORT_VERSION_MINOR);
> > - ver_release = inb(res->start + GMUX_PORT_VERSION_RELEASE);
> > - if (ver_major == 0xff && ver_minor == 0xff && ver_release
> > == 0xff) {
> > + if (!(~inl(res->start + GMUX_PORT_VERSION_MAJOR))) {
>
> Assuming we can get this tested well enough that I'm ok with the
> change in general please write this as:
>
> if (inl(res->start + GMUX_PORT_VERSION_MAJOR) == 0xffffffff) {
>
> Which I believe is what you are trying to achieve here ?
Yes that is a neater way of doing what I was trying to do, I'll use
that in v2.
>
> Regards,
>
> Hans
>
>
>
> > indexed = apple_gmux_is_indexed(res->start);
> > if (!indexed)
> > goto out;
>
