Re: [PATCH 1/1] usb: ulpi: don't register drivers if bus doesn't exist
On Thu, May 21, 2015 at 04:57:52PM +0800, Lu Baolu wrote: ULPI registers its bus at module_init, so if the bus fails to register, the module will fail to load and all will be well in the world. However, if the ULPI code is built-in rather than a module, the bus initialization may fail, but we'd still try to register drivers later onto a non-existent bus, which will panic the kernel. Fix that by checking that the bus was indeed initialized before trying to register drivers on top of it. Signed-off-by: Sasha Levin sasha.le...@oracle.com Signed-off-by: Heikki Krogerus heikki.kroge...@linux.intel.com Signed-off-by: Lu Baolu baolu...@linux.intel.com Reported-by: Zhuo Qiuxu qiuxu.z...@intel.com Reviewed-by: David Cohen david.a.co...@linux.intel.com --- drivers/usb/common/ulpi.c | 6 +- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c index 0e6f968..af52b46 100644 --- a/drivers/usb/common/ulpi.c +++ b/drivers/usb/common/ulpi.c @@ -132,6 +132,10 @@ int ulpi_register_driver(struct ulpi_driver *drv) if (!drv-probe) return -EINVAL; + /* Was the bus registered successfully? */ + if (unlikely(WARN_ON(!ulpi_bus.p))) never use unlikely/likely unless you can actually measure the difference if the marking is not used. Hint, on driver probe time, you can't. thanks, greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-usb in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 1/1] usb: ulpi: don't register drivers if bus doesn't exist
ULPI registers its bus at module_init, so if the bus fails to register, the module will fail to load and all will be well in the world. However, if the ULPI code is built-in rather than a module, the bus initialization may fail, but we'd still try to register drivers later onto a non-existent bus, which will panic the kernel. Fix that by checking that the bus was indeed initialized before trying to register drivers on top of it. Signed-off-by: Sasha Levin sasha.le...@oracle.com Signed-off-by: Heikki Krogerus heikki.kroge...@linux.intel.com Signed-off-by: Lu Baolu baolu...@linux.intel.com Reported-by: Zhuo Qiuxu qiuxu.z...@intel.com Reviewed-by: David Cohen david.a.co...@linux.intel.com --- drivers/usb/common/ulpi.c | 6 +- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c index 0e6f968..af52b46 100644 --- a/drivers/usb/common/ulpi.c +++ b/drivers/usb/common/ulpi.c @@ -132,6 +132,10 @@ int ulpi_register_driver(struct ulpi_driver *drv) if (!drv-probe) return -EINVAL; + /* Was the bus registered successfully? */ + if (unlikely(WARN_ON(!ulpi_bus.p))) + return -ENODEV; + drv-driver.bus = ulpi_bus; return driver_register(drv-driver); @@ -242,7 +246,7 @@ static int __init ulpi_init(void) { return bus_register(ulpi_bus); } -module_init(ulpi_init); +subsys_initcall(ulpi_init); static void __exit ulpi_exit(void) { -- 2.1.4 -- To unsubscribe from this list: send the line unsubscribe linux-usb in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/1] usb: ulpi: don't register drivers if bus doesn't exist
Hi Heikki, Sasha and others, Please ignore this patch. I should not squash these two patches into one and sign it off behalf of other people. I apologize for this and I'm sorry if this lets you feel affronted. Thanks, Baolu On 05/21/2015 04:57 PM, Lu Baolu wrote: ULPI registers its bus at module_init, so if the bus fails to register, the module will fail to load and all will be well in the world. However, if the ULPI code is built-in rather than a module, the bus initialization may fail, but we'd still try to register drivers later onto a non-existent bus, which will panic the kernel. Fix that by checking that the bus was indeed initialized before trying to register drivers on top of it. Signed-off-by: Sasha Levin sasha.le...@oracle.com Signed-off-by: Heikki Krogerus heikki.kroge...@linux.intel.com Signed-off-by: Lu Baolu baolu...@linux.intel.com Reported-by: Zhuo Qiuxu qiuxu.z...@intel.com Reviewed-by: David Cohen david.a.co...@linux.intel.com --- drivers/usb/common/ulpi.c | 6 +- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c index 0e6f968..af52b46 100644 --- a/drivers/usb/common/ulpi.c +++ b/drivers/usb/common/ulpi.c @@ -132,6 +132,10 @@ int ulpi_register_driver(struct ulpi_driver *drv) if (!drv-probe) return -EINVAL; + /* Was the bus registered successfully? */ + if (unlikely(WARN_ON(!ulpi_bus.p))) + return -ENODEV; + drv-driver.bus = ulpi_bus; return driver_register(drv-driver); @@ -242,7 +246,7 @@ static int __init ulpi_init(void) { return bus_register(ulpi_bus); } -module_init(ulpi_init); +subsys_initcall(ulpi_init); static void __exit ulpi_exit(void) { -- To unsubscribe from this list: send the line unsubscribe linux-usb in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/1] usb: ulpi: don't register drivers if bus doesn't exist
On Thu, May 21, 2015 at 06:07:25PM +0800, Lu, Baolu wrote: Hi Heikki, Sasha and others, Please ignore this patch. I should not squash these two patches into one and sign it off behalf of other people. I apologize for this and I'm sorry if this lets you feel affronted. No worries. So we'll use patch from Sasha to fix the panic when the bus is missing, and your's to fix the execution order. If you prepare v2 of your original patch, I'll ACK it. Thanks, -- heikki -- To unsubscribe from this list: send the line unsubscribe linux-usb in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html