[U-Boot] [PATCH] usb: ehci-mx6: Fix bus enumeration for DM case

[Marek Vasut]

On 6/21/19 3:45 AM, Peng Fan wrote:
> Hi Marek,
> 
>> -----Original Message-----
>> From: Marek Vasut [mailto:marex at denx.de]
>> Sent: 2019年6月21日 4:54
>> To: u-boot at lists.denx.de
>> Cc: Marek Vasut <marex at denx.de>; Abel Vesa <abel.vesa at nxp.com>; Adam
>> Ford <aford173 at gmail.com>; Fabio Estevam <festevam at gmail.com>;
>> Ludwig Zenz <lzenz at dh-electronics.com>; Peng Fan <peng.fan at nxp.com>;
>> Stefano Babic <sbabic at denx.de>; Vagrant Cascadian <vagrant at debian.org>
>> Subject: [PATCH] usb: ehci-mx6: Fix bus enumeration for DM case
>>
>> It is likely that the DM conversion of EHCI iMX6 driver was a derivative of EHCI
>> VF, however the conversion is incomplete and is missing the bind workaround,
>> which updates dev->seq number. Without this, all controllers have dev->seq
>> number 0 . Add this bind workaround into EHCI iMX6 driver as well.
>>
>> Signed-off-by: Marek Vasut <marex at denx.de>
>> Cc: Abel Vesa <abel.vesa at nxp.com>
>> Cc: Adam Ford <aford173 at gmail.com>
>> Cc: Fabio Estevam <festevam at gmail.com>
>> Cc: Ludwig Zenz <lzenz at dh-electronics.com>
>> Cc: Peng Fan <peng.fan at nxp.com>
>> Cc: Stefano Babic <sbabic at denx.de>
>> Cc: Vagrant Cascadian <vagrant at debian.org>
>> ---
>>  drivers/usb/host/ehci-mx6.c | 17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>>
>> diff --git a/drivers/usb/host/ehci-mx6.c b/drivers/usb/host/ehci-mx6.c index
>> 33abfeada0..109ed7ed4a 100644
>> --- a/drivers/usb/host/ehci-mx6.c
>> +++ b/drivers/usb/host/ehci-mx6.c
>> @@ -503,6 +503,22 @@ static int ehci_usb_ofdata_to_platdata(struct
>> udevice *dev)
>>  	return 0;
>>  }
>>
>> +static int ehci_usb_bind(struct udevice *dev) {
>> +	static int num_controllers;
>> +
>> +	/*
>> +	 * Without this hack, if we return ENODEV for USB Controller 0, on
>> +	 * probe for the next controller, USB Controller 1 will be given a
>> +	 * sequence number of 0. This conflicts with our requirement of
>> +	 * sequence numbers while initialising the peripherals.
>> +	 */
>> +	dev->req_seq = num_controllers;
> 
> With alias in dts, no need this, right?

There are no aliases in the DTs for the USB controllers, so that doesn't
help. I think for DM, the real solution would be to parse the PHY
phandle and pass around the PHY address instead of some arbitrary index,
but that's something to be done for next release. For this release, it's
only fixes.

Would you be interested in implementing the later for -next ? ;-)

-- 
Best regards,
Marek Vasut