[PATCH v1] T1024RDB: USB: Add a 10808 us delay in usb_scan_port

From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [PATCH v1] T1024RDB: USB: Add a 10808 us delay in usb_scan_port
Date: Mon, 16 Dec 2019 09:33:05 +0100	[thread overview]
Message-ID: <d8ea5c36-fec2-1375-5156-8bc7665e07d5@denx.de> (raw)
In-Reply-To: <CAEUhbmUoghvL_ub8dGqA6pucadpiHLaxJ6ghhQ_4YRmnxrtuTQ@mail.gmail.com>

On 12/16/19 4:17 AM, Bin Meng wrote:
> +Marek,
> 
> On Mon, Dec 16, 2019 at 11:13 AM Yinbo Zhu <yinbo.zhu@nxp.com> wrote:
>>
>> T1024RDB usb controller doesn't detect usb device at first usb start
>> Add a delay that is greater than 10808 us can fix that issue, which
>> delay if is less than 10808 us, issue is probabilistic occurrence
>>
>> => usb start
>> starting USB...
>> USB0:   USB EHCI 1.00
>> USB1:   USB EHCI 1.00
>> scanning bus 0 for devices... 1 USB Device(s) found
>> scanning bus 1 for devices... 1 USB Device(s) found
>>        scanning usb for storage devices... 0 Storage Device(s) found
>> => usb stop
>> stopping USB..
>> => usb start
>> starting USB...
>> USB0:   USB EHCI 1.00
>> USB1:   USB EHCI 1.00
>> scanning bus 0 for devices... 2 USB Device(s) found
>> scanning bus 1 for devices... 1 USB Device(s) found
>>        scanning usb for storage devices... 1 Storage Device(s) found
>> =>
>>
>> Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
>> ---
>>  common/usb_hub.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/common/usb_hub.c b/common/usb_hub.c
>> index 33aaeb8e44..6dd06696b2 100644
>> --- a/common/usb_hub.c
>> +++ b/common/usb_hub.c
>> @@ -486,6 +486,9 @@ static int usb_scan_port(struct usb_device_scan *usb_scan)
>>                 return 0;
>>         }
>>
>> +#ifdef CONFIG_TARGET_T1024RDB
>> +       udelay(10808);
>> +#endif
> 
> This looks like a workaround. Is this a silicon errata?

Does setting usb_pgood_delay to e.g. 2000 help ?