| Message ID | 1355412708-20046-4-git-send-email-kirill.shutemov@linux.intel.com |
|---|---|
| State | Rejected |
| Headers | show |
On Thu, Dec 13, 2012 at 05:31:48PM +0200, Kirill A. Shutemov wrote: > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > BIOS on Intel DZ77RE-75K motherboard notifies OS about Thunderbolt > hotplug before devices behind Thunderbolt are ready to be enumerated. > > Let's delay enumeration by 2 seconds. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > --- > drivers/pci/hotplug/acpiphp_glue.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > index 1a2b3ca..165987a 100644 > --- a/drivers/pci/hotplug/acpiphp_glue.c > +++ b/drivers/pci/hotplug/acpiphp_glue.c > @@ -49,6 +49,7 @@ > #include <linux/mutex.h> > #include <linux/slab.h> > #include <linux/acpi.h> > +#include <linux/dmi.h> > > #include "../pci.h" > #include "acpiphp.h" > @@ -1327,6 +1328,19 @@ out: > static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, > void *context) > { > + unsigned long delay = 0; > + const char *board_name; > + > + board_name = dmi_get_system_info(DMI_BOARD_NAME); > + /* > + * BIOS on Intel DZ77RE-75K motherboard notifies OS about Thunderbolt > + * hotplug before devices behind Thunderbolt are ready to be > + * enumerated. > + * Let's delay enumeration by 2 seconds. > + */ > + if (board_name && !strcmp(board_name, "DZ77RE-75K")) > + delay = 2 * HZ; Again, no objection to this patch as-is, but should we make it a bit more "general" and provide a quirk table to make this type of fix easier for other motherboards? Shouldn't we also match on a manufacturer field as well as the board_name? The kernel provides a very easy to match on any arbritary set of DMI fields for this kind of problem that we could use here. I can make that change if needed. What are the odds that other boards are going to need a longer delay time? Actually, is there a spec saying how long we need to wait? The ACPI PCI Hotplug had a value somewhere that the hardware was supposed to follow, but I don't have access to that ACPI spec anymore to verify this... thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 1a2b3ca..165987a 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -49,6 +49,7 @@ #include <linux/mutex.h> #include <linux/slab.h> #include <linux/acpi.h> +#include <linux/dmi.h> #include "../pci.h" #include "acpiphp.h" @@ -1327,6 +1328,19 @@ out: static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, void *context) { + unsigned long delay = 0; + const char *board_name; + + board_name = dmi_get_system_info(DMI_BOARD_NAME); + /* + * BIOS on Intel DZ77RE-75K motherboard notifies OS about Thunderbolt + * hotplug before devices behind Thunderbolt are ready to be + * enumerated. + * Let's delay enumeration by 2 seconds. + */ + if (board_name && !strcmp(board_name, "DZ77RE-75K")) + delay = 2 * HZ; + /* * Currently the code adds all hotplug events to the kacpid_wq * queue when it should add hotplug events to the kacpi_hotplug_wq. @@ -1336,7 +1350,7 @@ static void handle_hotplug_event_bridge(acpi_handle handle, u32 type, * don't deadlock on hotplug actions. */ alloc_acpiphp_hp_work(handle, type, context, - _handle_hotplug_event_bridge, 0); + _handle_hotplug_event_bridge, delay); } static void _handle_hotplug_event_func(struct work_struct *work)