Re: [PATCH 2/2] usb: gadget: function: f_fs: pass companion descriptor along

[Felipe Balbi <felipe.balbi@linux.intel.com>]

Hi,

Krzysztof Opasiak <k.opasiak@samsung.com> writes:
> On 01/31/2017 02:08 PM, Felipe Balbi wrote:
>> If we're dealing with SuperSpeed endpoints, we need
>> to make sure to pass along the companion descriptor
>> and initialize fields needed by the Gadget
>> API. Eventually, f_fs.c should be converted to use
>> config_ep_by_speed() like all other functions,
>> though.
>> 
>> Cc: <stable@vger.kernel.org>
>> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
>> ---
>> 
>> Will be sent in a pull request during v4.11-rc
>> 
>>  drivers/usb/gadget/function/f_fs.c | 15 +++++++++++++--
>>  1 file changed, 13 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
>> index 87fccf611b69..86aba2ebb3ef 100644
>> --- a/drivers/usb/gadget/function/f_fs.c
>> +++ b/drivers/usb/gadget/function/f_fs.c
>> @@ -1833,11 +1833,14 @@ static int ffs_func_eps_enable(struct ffs_function *func)
>>  	spin_lock_irqsave(&func->ffs->eps_lock, flags);
>>  	while(count--) {
>>  		struct usb_endpoint_descriptor *ds;
>> +		struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
>> +		int needs_comp_desc = false;
>>  		int desc_idx;
>>  
>> -		if (ffs->gadget->speed == USB_SPEED_SUPER)
>> +		if (ffs->gadget->speed == USB_SPEED_SUPER) {
>>  			desc_idx = 2;
>> -		else if (ffs->gadget->speed == USB_SPEED_HIGH)
>> +			needs_comp_desc = true;
>> +		} else if (ffs->gadget->speed == USB_SPEED_HIGH)
>>  			desc_idx = 1;
>>  		else
>>  			desc_idx = 0;
>> @@ -1854,6 +1857,14 @@ static int ffs_func_eps_enable(struct ffs_function *func)
>>  
>>  		ep->ep->driver_data = ep;
>>  		ep->ep->desc = ds;
>> +
>> +		comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
>> +				USB_DT_ENDPOINT_SIZE);
>> +		ep->ep->maxburst = comp_desc->bMaxBurst + 1;
>> +
>> +		if (needs_comp_desc)
>> +			ep->ep->comp_desc = comp_desc;
>> +
>
> Please correct me if I'm wrong but wouldn't we read rubbish here if user
> provided us SS ep descriptor without companion descriptor?

companion desc is required for SS endpoints, it's also required that
they follow EP desc. If user doesn't write it, don't they deserve the
errors they'll have?

-- 
balbi