On 13/06/17 10:37, Hans de Goede wrote:
> Commit e5bbf30733f9 ("mmc: sdhci-acpi: Ensure connected devices are
> powered when probing") introduced unconditional calling of
> acpi_device_fix_up_power() on the mmc controller and its children.
>
> This broke wifi on some systems because acpi_device_fix_up_power()
> was called even for disabled children sometimes leaving gpio-s in
> a state where wifi would not work, this was fixed in
> commit e1d070c3793a ("mmc: sdhci-acpi: Only powered up enabled acpi
> child devices").
>
> Unfortunately on some devices calling acpi_device_fix_up_power()
> still causes issues. Specifically on the GPD-win mini clam-shell PC
> which has a pci-e wifi module, it causes the wifi module to get
> turned off. This is a BIOS bug and I've tried to get the manufacturer
> to fix this but sofar they have not responded (and even if they do
> then we cannot assume all users will update their BIOS).
>
> Since the GPD-win uses a pci-e wifi module the sdhci controller for
> sdio cards really should not get initialized on it at all.
>
> This commit adds a new sdhci_acpi.blacklist module option which can
> be set to an ACPI hid:uid pair, e.g. "80860F14:2" to disable probing
> for the sdhci host matching the hid:uid pair, fixing the wifi not
> working on this machine.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Apart from minor comments below:
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> Changes in v2:
> -Make the module option take a hid:uid pair string, instead of it
> being a boolean option, so that it only applies to one host
>
> Changes in v3:
> -Make the module option skip probing the device entirely (return -ENODEV)
>
> Changes in v4:
> -Fix bad seperator (now hid_end) check
> -Allow passing multiple HID:UID pairs seperated by commas
>
> Changes in v5:
> -Fix of by one error in parsing the string
> -Better commit subject
> ---
> drivers/mmc/host/sdhci-acpi.c | 46 ++++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 43 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
> index 89d9a8c014f5..9a1e0453cce4 100644
> --- a/drivers/mmc/host/sdhci-acpi.c
> +++ b/drivers/mmc/host/sdhci-acpi.c
> @@ -83,6 +83,39 @@ struct sdhci_acpi_host {
> bool use_runtime_pm;
> };
>
> +static char *blacklist;
> +
> +static bool sdhci_acpi_compare_hid_uid(const char *match, const char *hid,
> + const char *uid)
> +{
> + const char *hid_end, *uid_end, *end;
> +
> + if (!match || !hid || !uid)
> + return false;
> +
> + end = match + strlen(match);
> +
> + do {
> + hid_end = strchr(match, ':');
> + if (!hid_end)
> + return false;
> +
> + uid_end = strchr(hid_end, ',');
> + if (!uid_end)
> + uid_end = end;
> +
> + if (strlen(hid) == (hid_end - match) &&
Redundant ()
> + strncmp(match, hid, hid_end - match) == 0 &&
> + strlen(uid) == (uid_end - hid_end - 1) &&
Redundant ()
> + strncmp(hid_end + 1, uid, uid_end - hid_end - 1) == 0)
> + return true;
> +
> + match = uid_end + 1;
> + } while (uid_end != end);
> +
> + return false;
> +}
> +
> static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
> {
> return c->slot && (c->slot->flags & flag);
> @@ -378,6 +411,7 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> acpi_handle handle = ACPI_HANDLE(dev);
> + const char *bl = blacklist;
Redundant bl
> struct acpi_device *device, *child;
> struct sdhci_acpi_host *c;
> struct sdhci_host *host;
> @@ -390,6 +424,12 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
> if (acpi_bus_get_device(handle, &device))
> return -ENODEV;
>
> + hid = acpi_device_hid(device);
> + uid = device->pnp.unique_id;
> +
> + if (sdhci_acpi_compare_hid_uid(bl, hid, uid))
> + return -ENODEV;
> +
> /* Power on the SDHCI controller and its children */
> acpi_device_fix_up_power(device);
> list_for_each_entry(child, &device->children, node)
> @@ -399,9 +439,6 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
> if (sdhci_acpi_byt_defer(dev))
> return -EPROBE_DEFER;
>
> - hid = acpi_device_hid(device);
> - uid = device->pnp.unique_id;
> -
> iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!iomem)
> return -ENOMEM;
> @@ -580,6 +617,9 @@ static struct platform_driver sdhci_acpi_driver = {
>
> module_platform_driver(sdhci_acpi_driver);
>
> +module_param(blacklist, charp, 0444);
> +MODULE_PARM_DESC(blacklist, "ACPI <HID:UID>[,HID:UID] which should be ignored");
> +
> MODULE_DESCRIPTION("Secure Digital Host Controller Interface ACPI driver");
> MODULE_AUTHOR("Adrian Hunter");
> MODULE_LICENSE("GPL v2");
>
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