From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from helium.openadk.org (helium.openadk.org [89.238.66.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1EA6D4C81 for ; Thu, 12 Feb 2026 07:35:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=89.238.66.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770881747; cv=none; b=MfU6ygYc5wAmv7jqkU0sN6dmGIWzgVd8VUW4q2Gj7bS7y4sjXPhLLY/7OOP1ezudW7XZItOWJTRNEHQT66TOBBKEOMW6oJBlco4FXZd3kHgx8chrYGwkdz2zxb4l7AAxFAMbx/ROWaIudOFIkwYwxryMdgLPPRxhmFs/KZC70V8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770881747; c=relaxed/simple; bh=1nECUq3/i4vS53MxUHV0iksK7E1k69rKV/COVpMNWTg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LMRqu3PIdl+HAIQehk3FCrKg6ltqCy8a2vSlcQ1BF5+fyJIogyMtJHz7ETFHNkRjDnufQemHfHU5UpHdFUignVHFvFgcyTYXB2N8VE0ikuhO0ztECv1T40FKgBhOXm9ijDrrrQFvi+PX5bswSmJrwGWEgEnf9eagTEXP1DpWNWQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=openadk.org; spf=pass smtp.mailfrom=openadk.org; dkim=fail (0-bit key) header.d=openadk.org header.i=@openadk.org header.b=twHYNbCr reason="key not found in DNS"; arc=none smtp.client-ip=89.238.66.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=openadk.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=openadk.org Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=openadk.org header.i=@openadk.org header.b="twHYNbCr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=openadk.org; s=2022; t=1770881736; bh=1nECUq3/i4vS53MxUHV0iksK7E1k69rKV/COVpMNWTg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=twHYNbCrjWOxZvIRofOCB2BtDGR3azXMq9tedoUHrFlppzVpZSQlW0khyiM8kNj2+ SSRmCmmz5ctCJtQzzFJOdWkXaT0EgiIRoj7Gh6KZXJ0HZ/w2tkGMt0hFUoDGd0aZLt TGLfqEoL/H9bD9p/yF5p+zpggsQn1yhdUh6mV/Yqs0Qt1UkH8mqGFlCyAbEgxqt3EX +mRXP5Iwmvc2QN6uVxqJ9fXc9V4VDKpiOH5MI5jJZKsdZx3htULQsCBvYBjpvSen21 brWnr2SO2QbqTJqVu3gJJGUqbYA6Y1JCkzYSrzM38Rr0PG24vNCkB8v2xbBjmwwk8C LxGd14nxtIBZQ== Received: by helium.openadk.org (Postfix, from userid 1000) id 747B231E0B9B; Thu, 12 Feb 2026 08:35:36 +0100 (CET) Date: Thu, 12 Feb 2026 08:35:36 +0100 From: Waldemar Brodkorb To: Waldemar Brodkorb Cc: Jonas Gorski , Jiaxun Yang , "linux-mips@vger.kernel.org" Subject: Re: serial console on Mikrotik RB532 non-working Message-ID: References: <1e9086c1-0cec-4aa7-aab6-e1e605dd9ebf@app.fastmail.com> Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Operating-System: Linux 6.12.63+deb13-amd64 x86_64 Hi, friendly ping. Nobody has an idea how to fix it without revert? best regards Waldemar Waldemar Brodkorb wrote, > Hi Mips people, > Jonas Gorski wrote, > > > On Wed, Feb 4, 2026 at 12:19 PM Waldemar Brodkorb wrote: > > > > > > Hi Jonas, > > > Jonas Gorski wrote, > > > > > > > Hi, > > > > > > > > On Tue, Feb 3, 2026 at 7:25 PM Waldemar Brodkorb wrote: > > > > > > > > > > Hi Jiaxun, > > > > > Jiaxun Yang wrote, > > > > > > > > > > > > On Tue, 3 Feb 2026, at 3:24 PM, Jiaxun Yang wrote: > > > > > > > On Sun, 1 Feb 2026, at 6:39 PM, Waldemar Brodkorb wrote: > > > > > > >> Hi MIPS hackers, > > > > > > >> > > > > > > >> I want to use the latest Linux kernel on my Mikrotik RB532, but the > > > > > > >> serial console is non working. I bisected the problem and the first > > > > > > >> breaking change is this commit: > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > Can you try this? > > > > > > > > > > > > Oops sorry I missed a flag, it should be: > > > > > > > > > > > > diff --git a/arch/mips/rb532/devices.c b/arch/mips/rb532/devices.c > > > > > > index 8ecb56be81ac..239018540221 100644 > > > > > > --- a/arch/mips/rb532/devices.c > > > > > > +++ b/arch/mips/rb532/devices.c > > > > > > @@ -213,11 +213,12 @@ static struct platform_device rb532_wdt = { > > > > > > static struct plat_serial8250_port rb532_uart_res[] = { > > > > > > { > > > > > > .type = PORT_16550A, > > > > > > - .membase = (char *)KSEG1ADDR(REGBASE + UART0BASE), > > > > > > + .mapbase = REGBASE + UART0BASE, > > > > > > + .mapsize = SZ_4K, > > > > > > .irq = UART0_IRQ, > > > > > > .regshift = 2, > > > > > > .iotype = UPIO_MEM, > > > > > > - .flags = UPF_BOOT_AUTOCONF, > > > > > > + .flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP, > > > > > > }, > > > > > > { > > > > > > .flags = 0, > > > > > > > > > > > > > > > > I tried the patch, but it still hangs here: > > > > > > > > > > RouterBOOT booter 2.18 > > > > > > > > > > RouterBoard 532 > > > > > > > > > > CPU frequency: 399 MHz > > > > > Memory size: 32 MB > > > > > > > > > > Press any key within 3 seconds to enter setup... > > > > > trying dhcp protocol... OK > > > > > resolved mac address 9C:BF:0D:00:D6:4E > > > > > Gateway: 192.168.1.254 > > > > > transfer started ........................................ transfer ok, time=525.70s > > > > > setting up elf image... OK > > > > > jumping to kernel code > > > > > > > > > > Nothing in tcpdump tries to mount nfs, so I believe serial console > > > > > breakage is not the only problem here. > > > > > > > > Have you tried the patch on top of master or > > > > 6e690d54cfa802f939cefbd2fa2c91bd0b8bd1b6? > > > > > > > > If it works on top of 6e690d54cfa802f939cefbd2fa2c91bd0b8bd1b6, then > > > > it fixes the serial issue, and you can do a new git bisect between > > > > 6e690d54cfa802f939cefbd2fa2c91bd0b8bd1b6 and master to find the next > > > > breakage, with the patch re-applied on top each step (so serial stays > > > > working). > > > > > > Yes, thanks for the idea. I already had this idea in mind and I am 9 > > > steps before I get the next breakage :) > > > > > > Thanks for the heads up, > > > > Also a small warning when doing a bisect with git am'd patches on top: > > always (git) reset to the original tested commit before doing git > > bisect , else git bisect will account for these commits on > > top in calculating the next revision to test and may suggest the very > > same commit again you were originally testing. > > > > It took a me a few steps until I noticed I was running in circles when > > I had to bisect with a few patches on top. > > I just used patch and git stash for the job :) > So here is the result, the failing commit is: > commit 9f048fa487409e364cf866c957cf0b0d782ca5a3 (HEAD) > Author: Maciej W. Rozycki > Date: Thu Nov 13 05:21:10 2025 +0000 > > MIPS: mm: Prevent a TLB shutdown on initial uniquification > > Depending on the particular CPU implementation a TLB shutdown may occur > if multiple matching entries are detected upon the execution of a TLBP > or the TLBWI/TLBWR instructions. Given that we don't know what entries > we have been handed we need to be very careful with the initial TLB > setup and avoid all these instructions. > > Therefore read all the TLB entries one by one with the TLBR instruction, > bypassing the content addressing logic, and truncate any large pages in > place so as to avoid a case in the second step where an incoming entry > for a large page at a lower address overlaps with a replacement entry > chosen at another index. Then preinitialize the TLB using addresses > outside our usual unique range and avoiding clashes with any entries > received, before making the usual call to local_flush_tlb_all(). > > This fixes (at least) R4x00 cores if TLBP hits multiple matching TLB > entries (SGI IP22 PROM for examples sets up all TLBs to the same virtual > address). > > Signed-off-by: Maciej W. Rozycki > Fixes: 35ad7e181541 ("MIPS: mm: tlb-r4k: Uniquify TLB entries on init") > Cc: stable@vger.kernel.org > Reviewed-by: Jiaxun Yang > Tested-by: Jiaxun Yang # Boston I6400, M5150 sim > Signed-off-by: Thomas Bogendoerfer > > Reverting this commit, make the RB532 boot. I need the UART patch, too. > > Attached is the dmesg from the device. > > Anyone knows how to fix this issue? > > best regards > Waldemar > > > [ 0.000000] Linux version 6.19.0-rc8+ (wbx@fluor) (mipsel-openadk-linux-uclibc-gcc (GCC) 15.2.0, GNU ld (GNU Binutils) 2.45.1) #50 Wed Feb 4 16:41:19 CET 2026 > [ 0.000000] CPU0 revision is: 0001800a (MIPS 4Kc) > [ 0.000000] User-defined physical RAM map overwrite > [ 0.000000] Primary instruction cache 8kB, VIPT, 4-way, linesize 16 bytes. > [ 0.000000] Primary data cache 8kB, 4-way, VIPT, no aliases, linesize 16 bytes > [ 0.000000] Zone ranges: > [ 0.000000] Normal [mem 0x0000000000000000-0x0000000001ffffff] > [ 0.000000] Movable zone start for each node > [ 0.000000] Early memory node ranges > [ 0.000000] node 0: [mem 0x0000000000000000-0x0000000001ffffff] > [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000001ffffff] > [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 > [ 0.000000] pcpu-alloc: [0] 0 > [ 0.000000] Kernel command line: console=ttyS0,115200 gpio=16383 mem=32M kmac=00:0C:42:0A:7D:D3 board=500 boot=1 console=ttyS0,115200 rw root=/dev/nfs ip=dhcp nfsroot=192.168.1.254:/srv/nfs/rb532 > [ 0.000000] korina mac = 00:0C:42:0A:7D:D3 > [ 0.000000] Unknown kernel command line parameters "gpio=16383 board=500 boot=1", will be passed to user space. > [ 0.000000] printk: log buffer data + meta data: 131072 + 409600 = 540672 bytes > [ 0.000000] Dentry cache hash table entries: 4096 (order: 2, 16384 bytes, linear) > [ 0.000000] Inode-cache hash table entries: 2048 (order: 1, 8192 bytes, linear) > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 8192 > [ 0.000000] mem auto-init: stack:all(zero), heap alloc:off, heap free:off > [ 0.000000] SLUB: HWalign=16, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 > [ 0.000000] NR_IRQS: 256 > [ 0.000000] Initializing IRQ's: 168 out of 256 > [ 0.000000] calculating r4koff... > [ 0.000000] 000c34f8(799992) > [ 0.000000] CPU frequency 400.00 MHz > [ 0.000000] clocksource: MIPS: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 9556397797 ns > [ 0.000010] sched_clock: 32 bits at 200MHz, resolution 5ns, wraps every 10737525757ns > [ 0.000236] Calibrating delay loop... 397.82 BogoMIPS (lpj=795648) > [ 0.032139] pid_max: default: 32768 minimum: 301 > [ 0.033029] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) > [ 0.033136] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) > [ 0.042812] Memory: 26612K/32768K available (3993K kernel code, 542K rwdata, 548K rodata, 152K init, 188K bss, 5760K reserved, 0K cma-reserved) > [ 0.044819] devtmpfs: initialized > [ 0.053484] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns > [ 0.053636] posixtimers hash table entries: 512 (order: 0, 2048 bytes, linear) > [ 0.053740] futex hash table entries: 256 (4096 bytes on 1 NUMA nodes, total 4 KiB, linear). > [ 0.060069] NET: Registered PF_NETLINK/PF_ROUTE protocol family > [ 0.062045] gpio gpiochip0: Static allocation of GPIO base is deprecated, use dynamic allocation. > [ 0.064668] PCI: Initializing PCI > [ 0.070830] SCSI subsystem initialized > [ 0.071977] libata version 3.00 loaded. > [ 0.074816] PCI host bridge to bus 0000:00 > [ 0.074882] pci_bus 0000:00: root bus resource [mem 0x50000000-0x5fffffff] > [ 0.074978] pci_bus 0000:00: root bus resource [io 0x18800000-0x188fffff] > [ 0.075066] pci_bus 0000:00: No busn resource found for root bus, will use [bus 00-ff] > [ 0.075217] pci 0000:00:00.0: [111d:0000] type 00 class 0x000000 conventional PCI endpoint > [ 0.075353] pci 0000:00:00.0: BAR 0 [mem 0x00000000-0x07ffffff pref] > [ 0.075449] pci 0000:00:00.0: [Firmware Bug]: BAR 1: invalid; can't size > [ 0.075512] pci 0000:00:00.0: [Firmware Bug]: BAR 2: invalid; can't size > [ 0.101583] pci 0000:00:02.0: [1106:3106] type 00 class 0x020000 conventional PCI endpoint > [ 0.101736] pci 0000:00:02.0: BAR 0 [io 0x0000-0x00ff] > [ 0.101831] pci 0000:00:02.0: BAR 1 [mem 0x00000000-0x000000ff] > [ 0.102022] pci 0000:00:02.0: supports D1 D2 > [ 0.102087] pci 0000:00:02.0: PME# supported from D1 D2 D3hot D3cold > [ 0.102883] pci 0000:00:03.0: [1106:3106] type 00 class 0x020000 conventional PCI endpoint > [ 0.103036] pci 0000:00:03.0: BAR 0 [io 0x0000-0x00ff] > [ 0.103131] pci 0000:00:03.0: BAR 1 [mem 0x00000000-0x000000ff] > [ 0.103322] pci 0000:00:03.0: supports D1 D2 > [ 0.103386] pci 0000:00:03.0: PME# supported from D1 D2 D3hot D3cold > [ 0.104215] pci 0000:00:04.0: [13a3:0020] type 00 class 0x0b4000 conventional PCI endpoint > [ 0.104368] pci 0000:00:04.0: BAR 0 [mem 0x00000000-0x00000fff] > [ 0.104463] pci 0000:00:04.0: BAR 1 [mem 0x00000000-0x00001fff] > [ 0.104553] pci 0000:00:04.0: BAR 2 [mem 0x00000000-0x00007fff] > [ 0.584389] pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 00 > [ 0.584536] pci 0000:00:04.0: BAR 2 [mem 0x50000000-0x50007fff]: assigned > [ 0.584656] pci 0000:00:04.0: BAR 1 [mem 0x50008000-0x50009fff]: assigned > [ 0.584771] pci 0000:00:04.0: BAR 0 [mem 0x5000a000-0x5000afff]: assigned > [ 0.584887] pci 0000:00:02.0: BAR 0 [io 0x18800000-0x188000ff]: assigned > [ 0.585003] pci 0000:00:02.0: BAR 1 [mem 0x5000b000-0x5000b0ff]: assigned > [ 0.585119] pci 0000:00:03.0: BAR 0 [io 0x18800400-0x188004ff]: assigned > [ 0.585235] pci 0000:00:03.0: BAR 1 [mem 0x5000b100-0x5000b1ff]: assigned > [ 0.586040] clocksource: Switched to clocksource MIPS > [ 0.595022] NET: Registered PF_INET protocol family > [ 0.596277] IP idents hash table entries: 2048 (order: 2, 16384 bytes, linear) > [ 0.599075] tcp_listen_portaddr_hash hash table entries: 1024 (order: 0, 4096 bytes, linear) > [ 0.599207] Table-perturb hash table entries: 65536 (order: 6, 262144 bytes, linear) > [ 0.599357] TCP established hash table entries: 1024 (order: 0, 4096 bytes, linear) > [ 0.599483] TCP bind hash table entries: 1024 (order: 1, 8192 bytes, linear) > [ 0.599665] TCP: Hash tables configured (established 1024 bind 1024) > [ 0.600026] UDP hash table entries: 256 (order: 1, 8192 bytes, linear) > [ 0.600186] UDP-Lite hash table entries: 256 (order: 1, 8192 bytes, linear) > [ 0.601161] NET: Registered PF_UNIX/PF_LOCAL protocol family > [ 0.603686] RPC: Registered named UNIX socket transport module. > [ 0.603736] RPC: Registered udp transport module. > [ 0.603769] RPC: Registered tcp transport module. > [ 0.603802] RPC: Registered tcp-with-tls transport module. > [ 0.603835] RPC: Registered tcp NFSv4.1 backchannel transport module. > [ 0.603971] PCI: CLS 16 bytes, default 16 > [ 0.607134] workingset: timestamp_bits=30 max_order=13 bucket_order=0 > [ 0.613358] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled > [ 0.621159] printk: legacy console [ttyS0] disabled > [ 0.622542] serial8250.0: ttyS0 at MMIO 0x18058000 (irq = 104, base_baud = 12499875) is a 16550A > [ 0.622738] printk: legacy console [ttyS0] enabled > [ 1.299755] scsi host0: pata-rb532-cf > [ 1.305007] ata1: PATA max PIO4 irq 149 lpm-pol 0 > [ 1.313888] eth0: korina-0.20 15Sep2017 > [ 1.318861] via-rhine 0000:00:02.0: enabling device (0080 -> 0083) > [ 1.334840] via-rhine 0000:00:02.0 eth1: VIA Rhine III at (ptrval), 00:0c:42:0a:7d:d4, IRQ 142 > [ 1.345448] via-rhine 0000:00:02.0 eth1: MII PHY found at address 1, status 0x7849 advertising 05e1 Link 0000 > [ 1.356989] via-rhine 0000:00:03.0: enabling device (0080 -> 0083) > [ 1.372559] via-rhine 0000:00:03.0 eth2: VIA Rhine III at (ptrval), 00:0c:42:0a:7d:d5, IRQ 143 > [ 1.383162] via-rhine 0000:00:03.0 eth2: MII PHY found at address 1, status 0x7849 advertising 05e1 Link 0000 > [ 1.395174] rc32434_wdt: Stopped watchdog timer > [ 1.401166] rc32434_wdt: Watchdog Timer version 1.0, timer margin: 20 sec > [ 1.410007] NET: Registered PF_PACKET protocol family > [ 1.488756] korina korina eth0: link up, 100Mbps, full-duplex, lpa 0xFFFFFF6F > [ 1.514213] Sending DHCP requests ., OK > [ 1.542622] IP-Config: Got DHCP answer from 192.168.1.254, my address is 192.168.1.9 > [ 1.551409] IP-Config: Complete: > [ 1.555148] device=eth0, hwaddr=00:0c:42:0a:7d:d3, ipaddr=192.168.1.9, mask=255.255.255.0, gw=192.168.1.254 > [ 1.566657] host=192.168.1.9, domain=, nis-domain=(none) > [ 1.573201] bootserver=192.168.1.254, rootserver=192.168.1.254, rootpath= > [ 1.573275] nameserver0=192.168.1.254 > [ 1.588787] check access for rdinit=/init failed: -2, ignoring > [ 1.658499] VFS: Mounted root (nfs filesystem) on device 0:13. > [ 1.667866] devtmpfs: mounted > [ 1.671780] Freeing unused kernel image (initmem) memory: 152K > [ 1.677854] This architecture does not have kernel memory protection. > [ 1.684548] Run /sbin/init as init process > [ 1.688861] with arguments: > [ 1.688920] /sbin/init > [ 1.688977] with environment: > [ 1.689027] HOME=/ > [ 1.689082] TERM=linux > [ 1.689137] gpio=16383 > [ 1.689193] board=500 > [ 1.689248] boot=1 > [ 1.723116] process '/bin/busybox' started with executable stack > [ 208.334338] random: crng init done