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We uncovered a limitation of this core WRT to the Link Layer Compliance Suite's TD7.06. On that test, host will start a GetDescriptor(DEVICE) standard request, but it will do so only on the SETUP phase, meaning there will *NOT* be any DATA or STATUS phases. The idea of the test is to verify robustness of the IP WRT framing errors, so the test will send a sequence of different SETUP_DPs each with a different framing error and the Suite expects us to be able to receive all SETUP_DPs with no timeouts. This core, has the ability to tell us which phase the host is expecting before we start it. Whenever we receive a TP or DP when no transfers are cached on the internal IP's caches, the IP will generate a XferNotReady event with status informing us (in case of physical ep0/ep1) if it's related to DATA or STATUS phases - SETUP phase is expected to be prestarted. Because we're always waiting for XferNotReady events for DATA and STATUS phases, we will never be able to know that the Host wants to start another SETUP phase instead, which will render us "not compliant" with TD7.06. In order to "fix" the problem we must not rely on XferNotReady events for the DATA phase and try to always pre-start DATA transfers on physical endpoints 0 and 1. If host goes back to SETUP phase from DATA phase we will receive a XferComplete for that phase with TRB's status set to SETUP_PENDING, which is only useful for printing a debugging log as the core expects us to still go through to the STATUS phase, initiate a CONTROL_STATUS TRB just so it completes right away and, only then, we go back to the pending SETUP phase. SNPS has decided to modify the programming model of the core so that on-demand DATA phases will not be supported anymore. Note that this limitation does not affect 2-stage transfers, meaning that if TD7.06 would start a 2-stage transfer instead of a 3-stage transfer, we would receive a "fake" XferNotReady(STATUS) which would complete right after being initiated with SETUP_PENDING status. Other endpoints are also not affected, so we can still use on-demand transfers on Bulk/Isoc/Interrupt endpoints. Signed-off-by: Felipe Balbi <balbi@ti.com> |
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| .. | ||
| core.c | ||
| core.h | ||
| debug.h | ||
| debugfs.c | ||
| dwc3-exynos.c | ||
| dwc3-omap.c | ||
| dwc3-pci.c | ||
| ep0.c | ||
| gadget.c | ||
| gadget.h | ||
| host.c | ||
| io.h | ||
| Kconfig | ||
| Makefile | ||