Congratulations Lup! I'm looking forward to see Star64 JH7110 integrated into mainline.
BR, Alan On 8/2/23, Lee, Lup Yuen <lu...@appkaki.com> wrote: > Thanks Tomek! Here's the backup link for the article (since Codeberg is > down): https://lupyuen.github.io/articles/plic > > I found out (from Hacker News) that JH7110 uses a Synopsys DesignWare 8250 > UART that has a peculiar problem with the Line Control Register (LCR)... If > we write to LCR while the UART is busy, it will trigger spurious UART > Interrupts. > > The fix is to wait for the UART to be not busy before writing to LCR. > Here's my proposed patch for the NuttX 16550 UART Driver > (drivers/serial/uart_16550.c): > https://github.com/lupyuen2/wip-pinephone-nuttx/pull/36/files#diff-f208234edbfb636de240a0fef1c85f9cecb37876d5bc91ffb759f70a1e96b1d1 > > We're all ready to merge NuttX for JH7110! :-) > > Lup > > On Wed, Aug 2, 2023 at 7:19 AM Tomek CEDRO <to...@cedro.info> wrote: > >> On Wed, Aug 2, 2023 at 1:14 AM Lee, Lup Yuen wrote: >> > NuttX on Star64 JH7110 RISC-V SBC is almost ready! But we're stuck with >> > 16550 UART Controller firing too many Spurious Interrupts. >> >> Good luck Lup! IRQ storm is (was?) known problem on a desktop machines >> too! I hope you fight that beast soon :-) :-) >> >> -- >> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info >> >
