From mboxrd@z Thu Jan 1 00:00:00 1970 From: dennis.borgmann@googlemail.com (Dennis Borgmann) Date: Mon, 25 Oct 2010 12:58:14 +0200 Subject: at91sam9g20 hangs at ohci-hcd In-Reply-To: <4CBDC1D8.6060706@atmel.com> References: <4CBDAA96.5060107@googlemail.com> <4CBDC1D8.6060706@atmel.com> Message-ID: <4CC562C6.5070107@googlemail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Nicolas, the problem has been solved by setting buildroot and the kernel to run on at91sam9260 instead of at91sam9g20. In addition, I had to make some adjustments at the clock.c sorcecode in the kernel, which needs to have some different timings. I cannot answer, why it is this way, but it works for me. Kind regards and thanks for your thoughts, Dennis Nicolas Ferre schrieb: > Hi, > > I answer as private message as I am not coming with a real answer... Just a hint that can help you go forward. > > Le 19/10/2010 16:26, Dennis Borgmann : > >> Hello linux-arm list! >> >> I am using an at91sam9g20-CPU on an "eddy-Board Version 2.5" from a >> company called "Systembase" - see http://www.embeddedmodule.com >> >> I am booting my system via u-boot http://www.denx.de/wiki/U-Boot >> >> The problem that I see is, that the kernel won't boot up to a login >> prompt, it simply hangs at the point, where it loads the USB driver >> 'ohci-hcd'. The last output I get from the kernel booting messages are >> appended below at the end of this mail. >> >> After searching the internet for two days now, I have given up the idea >> to solve the problem on my own. The problem seems to be known to the >> linux community, as I can find a link on this: >> >> https://bugzilla.kernel.org/show_bug.cgi?id=11041 >> >> People are talking about an endless loop involving modprobe at a certain >> point and the solution for them is to revert a previous commit to their >> code repository. This has been going on in 2008. Now, we have 2010 and I >> would suggest this problem being solved. But still I cannot get the >> board running. >> >> If I switch to an older release of the board - version 2.1, which >> contains an at91sam9260 - everything works fine. The problem appears >> with at91sam9g20. >> > > Strange. I did not test 9g20ek usb host recently but I cannot tell that I have a known issue... > > >> I am building my system with buildroot - http://buildroot.uclibc.org/ - >> , tried already several kernels (2.6.25.20, 2.6.27.54, 2.6.33.7 and >> 2.6.34.3) but none of them worked. I also tried giving buildroot a >> kernel path from this webpage: >> >> http://maxim.org.za/at91_26.html >> >> For a first test, I chose version 2.6.33, which did not solve my problem >> either. >> >> The code seems to hang in ohci-at91.c (for example located here: >> linux-2.6.33.7/drivers/usb/host/ ) in function 'static void >> at91_start_hc(struct platform_device *pdev)' . It can get up to line 69 >> ( 'writel(0, ®s->control);' ), but this call does not return. I found >> this out by giving the code several printk's. >> >> There is no difference, if I compile the driver as module or directly >> into the kernel. Either it hangs on boot-time or it hangs, when I do >> 'modprobe ohci-hcd'. >> >> I don't know any more things to do. Could you give me hint, where to >> search for my problem? It would be nice to be able to use kernel 2.6.34 >> due to wireless demands. >> > > I would advice you to test (even if you would prefer a newer kernel) > with 2.6.30 + at91 patches + "experimental" patches as described on > http://www.linux4sam.org > http://www.at91.com/linux4sam/bin/view/Linux4SAM/LinuxKernel#AT91_Linux_kernel_sources_summar > > Hope this helps, > > Best regards, >