Re: [RESENDING RFC PATCH 0/4] Add logic to consolidate TRBs for Synopsys xHC

[Tejas Joglekar <Tejas.Joglekar@synopsys.com>]

On 3/27/2020 2:58 PM, Greg KH wrote:
> On Fri, Mar 27, 2020 at 02:22:23PM +0530, Tejas Joglekar wrote:
>> The Synopsys xHC has an internal TRB cache of size TRB_CACHE_SIZE for
>> each endpoint. The default value for TRB_CACHE_SIZE is 16 for SS and 8
>> for HS. The controller loads and updates the TRB cache from the
>> transfer ring in system memory whenever the driver issues a start
>> transfer or update transfer command.
>>
>> For chained TRBs, the Synopsys xHC requires that the total amount of
>> bytes for all TRBs loaded in the TRB cache be greater than or equal to
>> 1 MPS. Or the chain ends within the TRB cache (with a last TRB).
>>
>> If this requirement is not met, the controller will not be able to
>> send or receive a packet and it will hang causing a driver timeout and
>> error.
>>
>> This patch set adds logic to the XHCI driver to detect and prevent this
>> from happening along with the quirk to enable this logic for Synopsys
>> HAPS platform.
>>
>> Based on Mathias's feedback on previous implementation where consolidation
>> was done in TRB cache, with this patch series the implementation is done
>> during mapping of the URB by consolidating the SG list into a temporary
>> buffer if the SG list buffer sizes within TRB_CACHE_SIZE is less than MPS.
>>
>>
>> Tejas Joglekar (4):
>>   dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl
>>   usb: xhci: Set quirk for XHCI_CONSOLIDATE_SG_LIST
>>   usb: dwc3: Add device property consolidate-sgl
>>   usb: xhci: Use temporary buffer to consolidate SG
>>
>> Resending as 'umlaut' is not accepted by some servers in email.
> 
> Only patch 4/4 seems to have gone through :(
> 

Resent the missing patches