Hi,
On Wednesday 29 July 2009, Pavel Roskin wrote:
> Unloading rt61pci can leave the device in such state that reloading
> rt61pci would fail to reinitialize it. Bogus data would be read from
> the EEPROM and the RF version won't be recognized. Only reboot would
> return the device to a sane state.
>
> It appears that it happens if rt61pci is unloaded while power saving is
> active. To initialize the device properly, SOFT_RESET_CSR should be set
> to the same value as rt61pci_config_ps() uses to wake up the device.
>
> Signed-off-by: Pavel Roskin <proski@xxxxxxx>
> ---
>
> I don't know what 0x00000007 is and I don't want to make up a name for
> it.
I'll look it up in the specification document.
> rt61pci_config_ps() does other things, but this is the minimal required
> change. If anyone has a specification for rt61, it should mention
> SOFT_RESET_CSR and possibly other registers to be set before EEPROM may
> be accessed.
>
> Please note that unloading rt61pci (as well as rt73usb) can trigger an
> oops or panic in sysfs code that I didn't have a chance to fix yet.
> It's very elusive and manifests differently every time. Fortunately
> (for everyone not debugging it), it's rare.
>
>
> drivers/net/wireless/rt2x00/rt61pci.c | 2 ++
> 1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
> index fb95b8c..f615fe6 100644
> --- a/drivers/net/wireless/rt2x00/rt61pci.c
> +++ b/drivers/net/wireless/rt2x00/rt61pci.c
> @@ -2600,6 +2600,8 @@ static int rt61pci_probe_hw(struct rt2x00_dev *rt2x00dev)
> {
> int retval;
>
> + rt2x00pci_register_write(rt2x00dev, SOFT_RESET_CSR, 0x00000007);
> +
> /*
> * Allocate eeprom data.
> */
The only comment about the patch at this time is that it might require a nice comment. ;)
I'll also think that perhaps a more generic approach is required where rt2x00lib forces
PS to be disabled before probe_hw(), just in case other hardware also have these problems.
Thanks,
Ivo
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