On 6/19/23 00:46, Anne Macedo wrote:
Cards based on Renesas uPD720202 have their firmware downloaded during boot by xhci-pci. At this step, the status of the firmware is read and it takes a while for this read to happen (up to a few seconds). The macros RENESAS_RETRY and RENESAS_DELAY are used to retry reading this status byte from PCI a few times. If it can't read the status byte in RENESAS_RETRY tries, it times out. However, since this may vary from card to card, these retry and delay values need to be tweaked. In order to avoid having to patch the code to change these values, CONFIG_USB_XHCI_PCI_RENESAS_RETRY and CONFIG_USB_XHCI_PCI_RENESAS_DELAY are introduced. If applied, this patch helps to fix errors such as: ROM Download Step 34 failed at position 136 bytes Firmware Download Step 2 failed at position 8 bytes with (-110) while loading xhci-pci when using these cards. This error in particular has been noticed by this e-mail [1]. [1] https://lore.kernel.org/lkml/20190626070658.GP2962@vkoul-mobl/
Can you tell me on what hardware (is it something older, with maybe a Synopsys/Designware PCIe host controller?) do you experience these errors and what delay+retry values are you configuring in order to get your DUT up an running? From what I can tell, the quoted [1] link to Vinod's mail was just an update during development. This was v3 of the patch series back then (and it went on to v10 I think, so this wasn't an issue with what's in the kernel right now). Note: If you are interested I still got the "uPD720201/uPD720202 User's Manual" back then from Renesas site. (Nowadays they want you to register or something.). This document was the base for the code and maybe there's something in there you can quote to extend the retries/delays. (From what I vaguely remember. Most of the transfer was fast and no retries where necessary, but some register write took so long. Vinod also posted hints about a newer firmware for the uPD720201/uPD720202. Have you tried that as well?) Regards, Christian
