Messages in this thread | | | Date | Mon, 19 Jun 2023 10:12:36 +0000 | From | Anne Macedo <> | Subject | Re: [PATCH] usb: host: xhci: parameterize Renesas delay/retry |
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On 19.06.2023 10:19, Christian Lamparter wrote: > 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?
It's a PH61 Rev 1.2 board with the Renesas uPD720201 host controller. I'm using 10 as the delay and 6000 as the retry. > > 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). >
I see. That was the only reference I found to the timeout error I was seeing, so that's why I decided to tweak these retry+delay values.
> 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.
Definitely interested! I did find a .pdf on Google though, I can check it.
> > (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?)
I was using the upd72020x-fw AUR package on my Arch Linux build, if that's any relevant. However, it's quite old and I don't really know how it works. I missed these hints, sorry, could you point me to them? > > Regards, > Christian
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