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: 21245df307cb ("ACPI: video: Add Apple GMUX brightness control detection") Link: https://lore.kernel.org/platform-driver-x86/20230123113750.462144-1-hdegoede@xxxxxxxxxx/ Reported-by: Emmanouil Kouroupakis <kartebi@xxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v2: - Fix leaking of adev reference returned by acpi_dev_get_first_match_dev() (Reported-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>) - Add list of known affected Apple models (Lukas Wunner) - Add Reported-by and Link tags --- drivers/platform/x86/apple-gmux.c | 70 +++++++------------------ include/linux/apple-gmux.h | 86 ++++++++++++++++++++++++++++++- 2 files changed, 102 insertions(+), 54 deletions(-) diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index a0af01f6a0fd..9333f82cfa8a 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -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")); diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h index 80efaaf89e07..1f68b49bcd68 100644 --- a/include/linux/apple-gmux.h +++ b/include/linux/apple-gmux.h @@ -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 */ -- 2.39.0
