Re: Crash with sata_sil24 driver

[Tejun Heo <tj@kernel.org>]

Hello,

(cc'ing Jesse)

On Tue, Nov 22, 2011 at 04:40:40PM +0530, Pratyush Anand wrote:
> > I am using various PCIe card based on Silicon Image 3124/3132 to
> > test my PCIe host. This card is working with most of my host controler.
> > I use sata_sil24 driver to enable the card, with one modification of
> > commenting line [pcie_set_readrq(pdev, 4096);]
> >
> > I had sent a patch for it , which is still unanswered.
> > http://comments.gmane.org/gmane.linux.kernel.pci/10300

Yeah, that's something lifted from proprietary driver and it's
likely to be wrong.  Jesse, is there a way to find out the safe
maximum value for readrq?  I'm a bit reluctant to drop it as pcie
variants of these chips are bottlenecked on the host bus pretty badly.

> > Anyway, this mail is regarding another issue.
> >
> > I am still having problem when I use above driver (with above patch),
> > in following
> > situation.
> >
> > My SOC is having cortex-a9 dual core. When I work with CPU freq 500
> > MHz, it works
> > well. But with 600 MHz it crashes. Crash log is at the end of mail.
> >
> > I did further debugging. I found that if I put some delay after
> > calling of sil24_init_controller(host); in function sil24_init_one, it
> > works well.
> >
> > My question is.
> > does sil24_init_controller insure perfact initilization?
> > or we missing to check some status register which might be needed
> > before ata_host_activate.
> > ----------------------------------------------------------------------------------------------------------------
> > Modules linked in:
> > CPU: 0    Not tainted  (2.6.37-lsp-3.2.2-rc-dirty #7)
> > PC is at sil24_scr_read+0x38/0x50
> > LR is at sil24_port_base+0x14/0x2c
> > pc : [<80255e10>]    lr : [<80255d44>]    psr: 80000013

Hmm... this is weird.  All init happens in the same thread.  There's
no race condition involved here.  I'm not too familiar with arm.  Can
you please track down what is causing the crash?  ie. is it memory
access to kernel data structure or io region?

Thanks.

-- 
tejun