Hi,
On 11/6/2020 9:36 PM, Tejas Joglekar wrote:

Hi Felipe,
On 10/28/2020 8:50 PM, Tejas Joglekar wrote:

quoted

Hi,
On 10/28/2020 8:12 PM, Mathias Nyman wrote:

quoted

On 27.10.2020 20.28, Tejas Joglekar wrote:

quoted

Hi Mathias,
On 10/16/2020 6:34 PM, Tejas Joglekar wrote:

quoted

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.

Changes since v4:
 - Updated [Patch 3/3] platform data structure initialization
 - Trivial changes in commit wordings

Changes since v3:
 - Removed the dt-binding patch
 - Added new patch to pass the quirk as platform data
 - Modified the patch to set the quirk

Changes since v2:
 - Modified the xhci_unmap_temp_buffer function to unmap dma and c
   the dma flag
 - Removed RFC tag

Changes since v1:
 - Comments from Greg are addressed on [PATCH 4/4] and [PATCH 1/4]
 - Renamed the property and quirk as in other patches based on [PATCH 1/4]



Tejas Joglekar (3):
  usb: xhci: Set quirk for XHCI_SG_TRB_CACHE_SIZE_QUIRK
  usb: xhci: Use temporary buffer to consolidate SG
  usb: dwc3: Pass quirk as platform data

 drivers/usb/dwc3/host.c      |  10 +++
 drivers/usb/host/xhci-plat.c |   3 +
 drivers/usb/host/xhci-ring.c |   2 +-
 drivers/usb/host/xhci.c      | 137 ++++++++++++++++++++++++++++++++++-
 drivers/usb/host/xhci.h      |   5 ++
 5 files changed, 155 insertions(+), 2 deletions(-)

I have removed the dependency on setting quirk through device tree binding
and added the quirk using platform data. Can you please review and if 
everything looks OK, can you please add this patch series to your tree?

Sure, there aren't any functional changes to xhci since v3 of this series right?
And if I remember correctly Felipe didn't have any objections to the dwc3 part either.

You are right, there are no functional changes to xhci since v3.

quoted

Felipe, do you want to take the 3/3 dwc3 patch separately after 1/3 and 2/3 are in, or should
I take them all, or ask if Greg would like to pick up this series?

How would you like Mathias to go about merging the patch series?

@Felipe: Any input on this ?


Thanks & Regards,

Tejas Joglekar