e1000 driver hangs during probe

[Lucas Stach]

Am Freitag, den 10.03.2017, 10:10 +0100 schrieb Uwe Kleine-König:
> On Thu, Mar 09, 2017 at 08:04:08PM -0800, Andrey Smirnov wrote:
> > On Thu, Mar 9, 2017 at 1:18 PM, Uwe Kleine-König
> > <u.kleine-koenig at pengutronix.de> wrote:
> > > Hello,
> > >
> > > I work with an i.MX6 based hardware that has an i210 pcie device with
> > > barebox 2016.11.0 (but there didn't happen anything relevant since them
> > > if I'm not mistaken). When enabling all necessary things to make the
> > > e1000 bind, the driver seems to hang. The problem is the following code
> > > in e1000_get_hw_eeprom_semaphore():
> > >
> > >         /* Get the FW semaphore. */
> > >         timeout = hw->eeprom.word_size + 1;
> > >         while (timeout) {
> > >                 swsm = e1000_read_reg(hw, E1000_SWSM);
> > >                 swsm |= E1000_SWSM_SWESMBI;
> > >                 e1000_write_reg(hw, E1000_SWSM, swsm);
> > >                 /* if we managed to set the bit we got the semaphore. */
> > >                 swsm = e1000_read_reg(hw, E1000_SWSM);
> > >                 if (swsm & E1000_SWSM_SWESMBI)
> > >                         break;
> > >
> > >                 udelay(50);
> > >                 timeout--;
> > >         }
> > >
> > > together with the fact that hw->eeprom.word_size is either 0x200000 or
> > > 0x400000. (I saw both values already in three runs) This value is setup
> > > in e1000_init_eeprom_params() in the hw->mac_type == e1000_igb case.
> > >
> > > When waiting log enough the code finally terminates with a failure.
> > >
> > > In my case there is an 8Mb-Flash equipped on NVM_* that isn't programmed
> > > yet. (M25PE80, Page size: 256 bytes, Subsector erase: 4KB, Sector erase: 64KB,
> > > Bulk erase: 8Mb)
> > >
> > > Is someone able to shed some light on where the problem is?
> > >
> > 
> > This might be a long shot, but when I was working with that exact
> > combination last year (this board
> > https://git.pengutronix.de/cgit/barebox/tree/arch/arm/boards/zii-imx6q-rdu2)
> > I ran into an issue where while the reads to PCI configuration space
> > would work and the card would enumerate, access to registers mapped
> > via any of the BARs would return bogus values. Through trial and error
> > I was able to come up with a empirical hack to "fix" the issue and was
> > able to continue working with the driver.
> > 
> > Several month later Lucas was asked to take a look at the issue and he
> > was able to figure out the underlying cause and posted a series of
> > patches fixing the problem:
> > 
> > http://lists.infradead.org/pipermail/barebox/2016-November/028438.html
> > 
> > For some reason I am not seeing that whole series even in the latest
> > master, let alone 2016.11 codebase, so just to rule out you running
> > into the same problem I did, I'd start by applying that whole series
> > to your Barebox and seeing if that improves things.
> 
> With these patches applied the problem is gone and I see:
> 
> 	e1000 pci-8086:1531.0: Unprogrammed Flash detected, limiting access to first 4KB
> 	0: EEPROM checksum is incorrect!
> 	0:   ...register was 0x0000, calculated 0xbaba
> 	e1000 pci-8086:1531.0: probe failed: Invalid argument
> 
> and I have
> 
> 	/ ls -l /dev/e1000-nor0 
> 	crw-------           4096 /dev/e1000-nor0
> 
> Thanks for your valuable hint.
> 
> Sascha: If you want, interpret this as "Tested-by:".

This series has already been applied for a long time. It found it's way
into the v2017.01.0 release.

Regards,
Lucas