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platform/x86: apple-gmux: Add apple_gmux_detect() helper 

Add a new (static inline) apple_gmux_detect() helper to apple-gmux.h
which can be used for gmux detection instead of apple_gmux_present().

The latter is not really reliable since an ACPI device with a HID
of APP000B is present on some devices without a gmux at all, as well
as on devices with a newer (unsupported) MMIO based gmux model.

This causes apple_gmux_present() to return false-positives on
a number of different Apple laptop models.

This new helper uses the same probing as the actual apple-gmux
driver, so that it does not return false positives.

To avoid code duplication the gmux_probe() function of the actual
driver is also moved over to using the new apple_gmux_detect() helper.

This avoids false positives (vs _HID + IO region detection) on:

MacBookPro5,4
https://pastebin.com/8Xjq7RhS

MacBookPro8,1
https://linux-hardware.org/?probe=e513cfbadb&log=dmesg

MacBookPro9,2
https://bugzilla.kernel.org/attachment.cgi?id=278961

MacBookPro10,2
https://lkml.org/lkml/2014/9/22/657

MacBookPro11,2
https://forums.fedora-fr.org/viewtopic.php?id=70142

MacBookPro11,4
https://raw.githubusercontent.com/im-0/investigate-card-reader-suspend-problem-on-mbp11.4/master/test-16/dmesg

Fixes: 21245df307 ("ACPI: video: Add Apple GMUX brightness control detection")
Link: https://lore.kernel.org/platform-driver-x86/20230123113750.462144-1-hdegoede@redhat.com/
Reported-by: Emmanouil Kouroupakis <kartebi@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230124105754.62167-3-hdegoede@redhat.com
This commit is contained in:
Hans de Goede 2023-01-24 11:57:53 +01:00
parent 39f5a81f7a
commit d143908f80
2 changed files with 102 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
drivers/platform/x86/apple-gmux.c
View File

@ -226,23 +226,6 @@ static void gmux_write32(struct apple_gmux_data *gmux_data, int port,
gmux_pio_write32(gmux_data, port, val);
}
static bool gmux_is_indexed(struct apple_gmux_data *gmux_data)
{
u16 val;
outb(0xaa, gmux_data->iostart + 0xcc);
outb(0x55, gmux_data->iostart + 0xcd);
outb(0x00, gmux_data->iostart + 0xce);
val = inb(gmux_data->iostart + 0xcc) |
(inb(gmux_data->iostart + 0xcd) << 8);
if (val == 0x55aa)
return true;
return false;
}
/**
* DOC: Backlight control
*
@ -582,60 +565,43 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
int ret = -ENXIO;
acpi_status status;
unsigned long long gpe;
bool indexed = false;
u32 version;
if (apple_gmux_data)
return -EBUSY;
if (!apple_gmux_detect(pnp, &indexed)) {
pr_info("gmux device not present\n");
return -ENODEV;
}
gmux_data = kzalloc(sizeof(*gmux_data), GFP_KERNEL);
if (!gmux_data)
return -ENOMEM;
pnp_set_drvdata(pnp, gmux_data);
res = pnp_get_resource(pnp, IORESOURCE_IO, 0);
if (!res) {
pr_err("Failed to find gmux I/O resource\n");
goto err_free;
}
gmux_data->iostart = res->start;
gmux_data->iolen = resource_size(res);
if (gmux_data->iolen < GMUX_MIN_IO_LEN) {
pr_err("gmux I/O region too small (%lu < %u)\n",
gmux_data->iolen, GMUX_MIN_IO_LEN);
goto err_free;
}
if (!request_region(gmux_data->iostart, gmux_data->iolen,
"Apple gmux")) {
pr_err("gmux I/O already in use\n");
goto err_free;
}
/*
* 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 = 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);
if (ver_major == 0xff && ver_minor == 0xff && ver_release == 0xff) {
if (gmux_is_indexed(gmux_data)) {
u32 version;
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 {
pr_info("gmux device not present\n");
ret = -ENODEV;
goto err_release;
}
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);
}
pr_info("Found gmux version %d.%d.%d [%s]\n", ver_major, ver_minor,
ver_release, (gmux_data->indexed ? "indexed" : "classic"));

86
include/linux/apple-gmux.h
View File

@ -8,6 +8,8 @@
#define LINUX_APPLE_GMUX_H
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/pnp.h>
#define GMUX_ACPI_HID "APP000B"
@ -35,14 +37,89 @@
#define GMUX_MIN_IO_LEN (GMUX_PORT_BRIGHTNESS + 4)
#if IS_ENABLED(CONFIG_APPLE_GMUX)
static inline bool apple_gmux_is_indexed(unsigned long iostart)
{
u16 val;
outb(0xaa, iostart + 0xcc);
outb(0x55, iostart + 0xcd);
outb(0x00, iostart + 0xce);
val = inb(iostart + 0xcc) | (inb(iostart + 0xcd) << 8);
if (val == 0x55aa)
return true;
return false;
}
/**
* apple_gmux_present() - detect if gmux is built into the machine
* apple_gmux_detect() - detect if gmux is built into the machine
*
* @pnp_dev: Device to probe or NULL to use the first matching device
* @indexed_ret: Returns (by reference) if the gmux is indexed or not
*
* Detect if a supported gmux device is present by actually probing it.
* This avoids the false positives returned on some models by
* apple_gmux_present().
*
* Return: %true if a supported gmux ACPI device is detected and the kernel
* was configured with CONFIG_APPLE_GMUX, %false otherwise.
*/
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;
bool indexed = false;
bool ret = false;
if (!pnp_dev) {
adev = acpi_dev_get_first_match_dev(GMUX_ACPI_HID, NULL, -1);
if (!adev)
return false;
dev = get_device(acpi_get_first_physical_node(adev));
acpi_dev_put(adev);
if (!dev)
return false;
pnp_dev = to_pnp_dev(dev);
}
res = pnp_get_resource(pnp_dev, IORESOURCE_IO, 0);
if (!res || resource_size(res) < GMUX_MIN_IO_LEN)
goto out;
/*
* 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) {
indexed = apple_gmux_is_indexed(res->start);
if (!indexed)
goto out;
}
if (indexed_ret)
*indexed_ret = indexed;
ret = true;
out:
put_device(dev);
return ret;
}
/**
* apple_gmux_present() - check if gmux ACPI device is present
*
* Drivers may use this to activate quirks specific to dual GPU MacBook Pros
* and Mac Pros, e.g. for deferred probing, runtime pm and backlight.
*
* Return: %true if gmux is present and the kernel was configured
* Return: %true if gmux ACPI device is present and the kernel was configured
* with CONFIG_APPLE_GMUX, %false otherwise.
*/
static inline bool apple_gmux_present(void)
@ -57,6 +134,11 @@ static inline bool apple_gmux_present(void)
return false;
}
static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, bool *indexed_ret)
{
return false;
}
#endif /* !CONFIG_APPLE_GMUX */
#endif /* LINUX_APPLE_GMUX_H */