Messages in this thread | | | Date | Mon, 19 Jun 2023 09:59:44 +0000 | From | retpolanne@posteo ... | Subject | Re: [PATCH] usb: host: xhci: parameterize Renesas delay/retry |
| |
On 19.06.2023 07:46, Greg Kroah-Hartman wrote: > On Sun, Jun 18, 2023 at 10:46:57PM +0000, 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. > > No, a build-time option that affects all devices controlled by this > driver is not how you handle this, sorry.
Sorry, I completely forgot that other environments might have multiple cards. Mine only has one and I was focused on making it work. > > Make this a dynamic value, either determined automatically by the > device > itself (as you know what device is being controlled), or worst case, a > sysfs attribute that you can modify if things are not working properly. >
I'll follow Christian's tip and check the uPD720202 user manual and see if there's something I can look for in order to make this value dynamic.
> But a build-time option will never work, as it will never be changed, > and it would not allow for multiple devices in the system that are > different. > > thanks, > > greg k-h
| |