On Thu, 22 Jul 2010 17:14:04 +0200 Antonio Ospite <ospite@xxxxxxxxxxxxxxxxx> wrote: > On Sun, 11 Jul 2010 10:13:56 +0200 > Robert Jarzmik <robert.jarzmik@xxxxxxx> wrote: > [...] > > Well, the UDC is responding to each request from the USB host by stalling the > > USB endpoint (and not by stalling the full kernel). This shows that at least > > kernel interrupts are still alive and working. > > > > > I noted that (either with or without this patch) a quite similar phone > > > works, it's Motorola A1200 and has a different bootloader. > > > Maybe comparing some registers can help here? > > > > I'm still not fully convinced the pxa27x_udc is blocking the kernel. As the > > interrupt is working properly, and the interrupt handler relies on a spinlock, > > the spinlock is correcly released after each interrupt, and the driver should > > work normally. > > Now, the interrupt "storm" could block the kernel. That would rather be an host > > issue. Did you try to connect your phone to another computer ? > > > > I would ask for a last test : on the first line of function pxa_udc_probe(), > > insert "return 0;". If kernel still stalls, the pxa27x-udc is not involved. > > > > By inserting that "return 0;" the kernel goes on and I can complete > booting. > > BTW, I added some dumb debug calls to see the driver functions sequence > on both a780 and a1200 and it turns out that on A1200 I don't have this > IRQ that makes the driver(?) crazy on a780, does this new info give any > new element to you to find out the root cause? The two phones have > slight different hardware tho. > > Here are the two calling sequences: > http://people.openezx.org/ao2/tmp/pxa27x-udc_BUG/udc_a780.txt > http://people.openezx.org/ao2/tmp/pxa27x-udc_BUG/udc_a1200.txt > After that I tried deferring request_irq until the gadget driver has been registered, and it seems to work I don't get the Oops anymore, I see this as a quickfix I don't know if I like it as it does not look correct to me, but it could be another element toward a proper solution. See the inlined patch: diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c index 85b0d89..f083c5e 100644 --- a/drivers/usb/gadget/pxa27x_udc.c +++ b/drivers/usb/gadget/pxa27x_udc.c @@ -1791,6 +1791,7 @@ static void udc_enable(struct pxa_udc *udc) udc->enabled = 1; } +static irqreturn_t pxa_udc_irq(int irq, void *_dev); /** * usb_gadget_register_driver - Register gadget driver * @driver: gadget driver @@ -1847,6 +1848,16 @@ int usb_gadget_register_driver(struct usb_gadget_driver *driver) if (should_enable_udc(udc)) udc_enable(udc); + + /* irq setup after old hardware state is cleaned up */ + retval = request_irq(udc->irq, pxa_udc_irq, + IRQF_SHARED, driver_name, udc); + if (retval != 0) { + dev_err(udc->dev, "%s: can't get irq %i, err %d\n", + driver_name, IRQ_USB, retval); + goto transceiver_fail; + } + return 0; transceiver_fail: @@ -2507,15 +2518,6 @@ static int __init pxa_udc_probe(struct platform_device *pdev) udc_init_data(udc); pxa_eps_setup(udc); - /* irq setup after old hardware state is cleaned up */ - retval = request_irq(udc->irq, pxa_udc_irq, - IRQF_SHARED, driver_name, udc); - if (retval != 0) { - dev_err(udc->dev, "%s: can't get irq %i, err %d\n", - driver_name, IRQ_USB, retval); - goto err_irq; - } - pxa_init_debugfs(udc); return 0; err_irq: -- Antonio Ospite http://ao2.it PGP public key ID: 0x4553B001 A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing?
Attachment:
pgp3I3sEaFHxv.pgp
Description: PGP signature
