Re: [PATCH] mmc: block: Use the mmc host device index as the mmcblk device index

[Adrian Hunter <adrian.hunter@intel.com>]

On 16/05/16 12:12, Adrian Hunter wrote:
> On 16/05/16 11:47, Ulf Hansson wrote:
>> + Nicholas Krause
>>
>> On 13 April 2016 at 20:19, Laszlo Fiat <laszlo.fiat@gmail.com> wrote:
>>> Adrian, Ulf,
>>>
>>> Here are the two v4.6-rc3 kernel dmesg with mmc-debug option, both
>>> without additional patches, one working case [1], one failing case
>>> [2], the working case has patch [3] reverted.
>>>
>>> I also uploaded the acpidump [4] for Teclast X80h Baytrail-T tablet.
>>>
>>> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=112571#c11
>>> [2]: https://bugzilla.kernel.org/show_bug.cgi?id=112571#c10
>>> [3]: patch 520bd7a8b4152aacfbd34eb7f7a447354b631039 ("mmc: core:
>>> Optimize boot time by detecting cards simultaneously")
>>> [4]: https://bugzilla.kernel.org/show_bug.cgi?id=112571#c12
>>>
>>
>> Adrian, did you manage to get some time to look into the debug data
>> from this issue?
> 
> Not yet.
> 
>> I understand if you have been busy and no worries, although I don't
>> know who else to ping about this.
> 
> I will have a look today.
> 
>>
>> I don't want to us revert 520bd7a8b4152aacfbd34eb7f7a447354b631039,
>> because I believe it will just hide the problem in sdhci(-acpi).
>> Instead, I intend to wait for a proper fix, does that sounds
>> reasonable to you as well?
> 
> Sure

Here is a patch that might help:

From: Adrian Hunter <adrian.hunter@intel.com>
Date: Mon, 16 May 2016 14:29:51 +0300
Subject: [PATCH] mmc: sdhci-acpi: Ensure connected devices are powered on
 before probing

Some devices connected to the SDHCI controller may have
separate enabling lines that are controlled through GPIO.
These devices need to be powered on and enabled before
probing. This is to ensure all devices connected can be
seen by the controller.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-acpi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index b2d70ba6caa7..2d1c4870c285 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -378,7 +378,7 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	acpi_handle handle = ACPI_HANDLE(dev);
-	struct acpi_device *device;
+	struct acpi_device *device, *child;
 	struct sdhci_acpi_host *c;
 	struct sdhci_host *host;
 	struct resource *iomem;
@@ -390,6 +390,11 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
 	if (acpi_bus_get_device(handle, &device))
 		return -ENODEV;
 
+	/* Power on the SDHCI controller and its children */
+	acpi_device_fix_up_power(device);
+	list_for_each_entry(child, &device->children, node)
+		acpi_device_fix_up_power(child);
+
 	if (acpi_bus_get_status(device) || !device->status.present)
 		return -ENODEV;
 
-- 
1.9.1