Re: [PATCH 1/3] usb: xhci: add quirk flag for broken PED bits

From: Roger Quadros
Date: Mon Nov 21 2016 - 06:51:54 EST


On 18/11/16 12:49, Sergei Shtylyov wrote:
> Hello.
>
> On 11/17/2016 6:01 PM, Roger Quadros wrote:
>
>> From: Felipe Balbi <balbi@xxxxxx>
>>
>> Some devices from Texas Instruments [1] suffer from
>> a silicon bug where Port Enabled/Disabled bit
>> should not be used to silence an erroneous device.
>>
>> The bug is so that if port is disabled with PED
>> bit, an IRQ for device removal (or attachment)
>> will never fire.
>>
>> Just for the sake of completeness, the actual
>> problem lies with SNPS USB IP and this affects
>> all known versions up to 3.00a. A separate
>> patch will be added to dwc3 to enabled this
>> quirk flag if version is <= 3.00a.
>>
>> [1] - AM572x Silicon Errata http://www.ti.com/lit/er/sprz429j/sprz429j.pdf
>> Section i896â USB xHCI Port Disable Feature Does Not Work
>>
>> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
>> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
>> ---
>> drivers/usb/host/xhci-hub.c | 6 ++++++
>> drivers/usb/host/xhci.h | 3 +++
>> 2 files changed, 9 insertions(+)
>>
>> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
>> index 0ef1690..c3c051d 100644
>> --- a/drivers/usb/host/xhci-hub.c
>> +++ b/drivers/usb/host/xhci-hub.c
>> @@ -458,6 +458,12 @@ static void xhci_disable_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
>> return;
>> }
>>
>> + if (xhci->quirks & XHCI_BROKEN_PORT_PED) {
>> + xhci_dbg(xhci, "Broken Port Enabled/Disabled, ignoring "
>> + "port disable request.\n");
>
> The messages shouldn't be broken up to facilitate grepping.
>
> [...]
>> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
>> index f945380..4f724aa 100644
>> --- a/drivers/usb/host/xhci.h
>> +++ b/drivers/usb/host/xhci.h
>> @@ -1656,6 +1656,9 @@ struct xhci_hcd {
>> #define XHCI_SSIC_PORT_UNUSED (1 << 22)
>> #define XHCI_NO_64BIT_SUPPORT (1 << 23)
>> #define XHCI_MISSING_CAS (1 << 24)
>> +/* For controller with a broken Port Disable implementation */
>> +#define XHCI_BROKEN_PORT_PED (1 << 21)
>
> Indent with tabs as above, please.
>
> [...]
>

Thanks. I've fixed both issues and sent a v2.

cheers,
-roger