On Thu, 20 Feb 2025 at 10:43, Peter Maydell <peter.mayd...@linaro.org> wrote: > > On Tue, 18 Feb 2025 at 13:54, Peter Maydell <peter.mayd...@linaro.org> wrote: > > > > On Mon, 17 Feb 2025 at 14:55, Peter Maydell <peter.mayd...@linaro.org> > > wrote: > > > > > > On Sat, 8 Feb 2025 at 16:39, Philippe Mathieu-Daudé <phi...@linaro.org> > > > wrote: > > > > > > > > Hi, > > > > > > > > This series add support for (async) FIFO on the transmit path > > > > of the PL011 UART. > > > > > > > > > > Applied to target-arm.next, thanks (with a couple of minor > > > tweaks to two of the patches). > > > > Unfortunately I seem to get failures in 'make check-functional' > > with the last patch of this series applied. > > I had a look at this this morning because I wondered if it > was a mistake in the style fixups I'd applied to the patches > on my end, and I found the bug fairly quickly. The problem is > that pl011_xmit() doesn't update the TXFE and TXFF FIFO empty/full > status flag bits when it removes characters from the FIFO. > So the guest kernel spins forever because TXFF is never unset. > > The following patch fixes this for me (and also makes us not > set INT_TX for the case where we couldn't send any bytes to > the chardev, which I noticed reading the code rather than > because it had any visible bad effects):
Hmm, but that's clearly not the only problem -- it fixed the "no output at all issue", but now I see a test failure because of garbled console output: 2025-02-20 10:34:51,562: Booting Linux on physical CPU 0x0 2025-02-20 10:34:51,563: Linux version 4.18.16-300.fc29.armv7hl (mockbu...@buildvm-armv7-06.arm.fedoraproject.org) (gcc version 8.2.1 20180801 (Red Hat 8.2.1-2) (GCC)) #1 SMP Sun Oct 21 00:56:28 UTC 2018 2025-02-20 10:34:51,563: CPU: ARMv7 Processor [414fc0f0] revision 0 (ARMv7), cr=10c5387d 2025-02-20 10:34:51,564: CPU: div instructions available: patching division code 2025-02-20 10:34:51,564: CPU: PIPT / VIPT nonaliasing data cache, PIPT instruction cache 2025-02-20 10:34:51,565: OF: fdt: Machine model: linux,dummy-virt 2025-02-20 10:34:51,565: Memory policy: Data cache writealloc 2025-02-20 10:34:51,565: efi: Getting EFI parameters from FDT: 2025-02-20 10:34:51,566: efi: UEFI not found. 2025-02-20 10:34:51,566: cma: aetrsv6i 2025-02-20 10:34:51,566: psci: oi ocdteofmT 2025-02-20 10:34:51,566: ps:Sv1ecdniwe^Mps:Usdvni spsc:rt gtnot psci: SMC Calling Conventiov0 2025-02-20 10:34:51,567: pec:Eee1pec pvls9 1 2865^MBul1olt bi4^MKerloa n:itte nltAA 2025-02-20 10:34:51,568: Det c stlere 3 rr4 5i 9(dr336bt)Memr 06112aib 6Keece11K ra0 ,21 sv,Kmrsv,Kim)Virtual kernel memory layout: 2025-02-20 10:34:51,568: vt :xf0 fa f00 0f00 30 (0M^M lm c00 0800xe0 0000 2M^M mue:x00 0f00 4B 2025-02-20 10:34:51,568: et x(tvl) (rl 97B 2025-02-20 10:34:51,569: n 0(trvl-xta) 0 0pv) 3 B 2025-02-20 10:34:51,570: bs prl-xta) 5 )random: get_random_u32 ca ___+:ag6 d=3MOes,P=,os^Mfta:aotg78ni 1asHierhlC pmti. RCrtcnC oN_S2orpi=. TasCebd 2025-02-20 10:34:51,571: RC jtgeeyor_o_a1 __d^MNRIS1 rr GIC physical location is 0x800000^MGIC2 n[mx00-02f,P81]arcte 1tm( nna65H(r.cemk0fffffacl:0d20,aish_o:6i M,routo1n per49419sn^MCocrm dexCalibrating delay ose eceiife..oIl2^Mpxdl6i3 2025-02-20 10:34:51,572: SertFmo ia^MYemgmdl 2025-02-20 10:34:51,572: SEn: ili.Moutcea b te 2(d:,4t^MMoupnch stlers14oe 9oeyo 2025-02-20 10:34:51,572: CP0Screv:iwein tuia norieI tst lrl 2025-02-20 10:34:51,573: /cpus/cpu@0 missing clock-frequen or^MCPU rd1c k i 00^MSetgptiintm rx30 000Hircc Cmento^MEF rc ln aae^Msm ii cdrCs.smp ohu1o, USMPTao1reo cvae(15. gP.CPUA U)tt Code.devtmpfs: initialize^Mmo4aheu pr3vit e0cloejfe s fffm_cs0fffm_d_:924250sfut stbs 2025-02-20 10:34:51,574: piclo:niidit uye 2025-02-20 10:34:51,574: DM tre vi^MNETeDM:rlae2 o tmi oerent aloaios 2025-02-20 10:34:51,574: audit: initializing netlink subsys (disabled) 2025-02-20 10:34:51,574: audit: type=2000 audit(0.480:1): sat=ntalzdadt_nbe= e=^Mcpuidl:usn oenrmnu 2025-02-20 10:34:51,574: No ATG? 2025-02-20 10:34:51,575: hw-brapit fud5(1rsrvd rapon n achon eitrs^Mhw-brapit:mxmmwthontsz s8bts^MSerial MAP01 Ap1:ttAA tMIO09000ud = 0) saP01 e1 2025-02-20 10:34:51,575: console [ttyAMA0] enabled 2025-02-20 10:34:51,668: cryptd: max_cpu_qlen set to 1000 2025-02-20 10:34:51,690: vgaarb: loaded 2025-02-20 10:34:51,697: SCSI subsystem initialized 2025-02-20 10:34:51,702: usbcore: registered new interface driver usbfs 2025-02-20 10:34:51,703: usbcore: registered new interface driver hub (the log has no garbling after that so it's presumably OK with the interrupt-driven real UART driver but the polling one you get for earlycon has trouble.) I also noticed that pl011_write_txdata() doesn't clear TXFE when it puts a byte into the fifo -- I'm testing to see if fixing that helps. -- PMM
