Previously a patch series was sent up to change the way that DROM was read to prefer directly from NVM instead of bit banging. This series was produced due to issues found where TBT3 DROM CRC wouldn't match. In looking at it from USB4 analyzer the DROM wasn't corrupted before it arrived at the router. In analyzing the failure mode, every single failure occurred during a retried TX because RX interrupt "never came". This was actually a smoking gun; when the hardware responded too quickly both TX and RX interrupt status bits were set before the ISR would run. By the ISR using auto clear on read to process the TX this would make the RX interrupt bit get lost and the RX interrupt was never handled. To fix this issue, disable auto clear in the ISR and instead only clear the interrupt that is actually triggering the ISR. This fixes the communication for a long series of transactions such as bit banging and probably also fixes other situations that control transfers were retried a number of times due to a missing RX. Mario Limonciello (2): thunderbolt: Use const qualifier for `ring_interrupt_index` thunderbolt: Disable interrupt auto clear for rings drivers/thunderbolt/nhi.c | 42 +++++++++++++++++++++------------- drivers/thunderbolt/nhi_regs.h | 6 +++-- 2 files changed, 30 insertions(+), 18 deletions(-) -- 2.25.1
