Hi Eugeniu, On Wed, Jun 26, 2019 at 8:15 PM Eugeniu Rosca <roscaeuge...@gmail.com> wrote: > On Mon, Jun 24, 2019 at 02:38:18PM +0200, Geert Uytterhoeven wrote: > [..] > > - if (rchan->mid_rid < 0 || !sg_len) { > > + if (rchan->mid_rid < 0 || !sg_len || !sg_dma_len(sgl)) { > > dev_warn(chan->device->dev, > > "%s: bad parameter: len=%d, id=%d\n", > > __func__, sg_len, rchan->mid_rid); > > Just wanted to share the WARN output proposed by Wolfram in > https://patchwork.kernel.org/patch/11012991/#22721733 > in case the issue discussed in [1] is reproduced with this patch:
I'm not such a big fan of WARN()... > [ 2.065337] ------------[ cut here ]------------ > [ 2.065346] rcar_dmac_prep_slave_sg: <here-comes-the-warning-message> > [ 2.065394] WARNING: CPU: 2 PID: 252 at drivers/dma/sh/rcar-dmac.c:1169 > rcar_dmac_prep_slave_sg+0x50/0xc4 > [ 2.065397] Modules linked in: > [ 2.065407] CPU: 2 PID: 252 Comm: kworker/2:1 Not tainted > 5.2.0-rc6-00016-g2bfb85ba1481-dirty #26 > [ 2.065410] Hardware name: Renesas H3ULCB Kingfisher board based on > r8a7795 ES2.0+ (DT) > [ 2.065420] Workqueue: events sci_dma_tx_work_fn > [ 2.065425] pstate: 40000005 (nZcv daif -PAN -UAO) > [ 2.065430] pc : rcar_dmac_prep_slave_sg+0x50/0xc4 > [ 2.065434] lr : rcar_dmac_prep_slave_sg+0x50/0xc4 > [ 2.065436] sp : ffff0000112ebd00 > [ 2.065438] x29: ffff0000112ebd00 x28: 0000000000000000 > [ 2.065443] x27: ffff8006fa367138 x26: ffff000010c5bce8 > [ 2.065447] x25: 0000000738b1d000 x24: 0000000000000000 > [ 2.065451] x23: ffff000010b76e00 x22: ffff000010a18000 > [ 2.065455] x21: 0000000000000001 x20: ffff8006f9b5a080 > [ 2.065459] x19: ffff0000107adc86 x18: 0000000000000000 > [ 2.065462] x17: 0000000000000000 x16: 0000000000000000 > [ 2.065466] x15: 0000000000000000 x14: 0000000000000000 > [ 2.065469] x13: 0000000000040000 x12: ffff000010a35000 > [ 2.065473] x11: ffff000010b12981 x10: 0000000000000040 > [ 2.065477] x9 : 000000000000013e x8 : ffff000010b1b73b > [ 2.065481] x7 : 0000000000000000 x6 : 0000000000000001 > [ 2.065484] x5 : ffff8006ff72f7c0 x4 : 0000000000000001 > [ 2.065488] x3 : 0000000000000007 x2 : 0000000000000007 > [ 2.065491] x1 : 878c73041cedc400 x0 : 0000000000000000 > [ 2.065495] Call trace: > [ 2.065500] rcar_dmac_prep_slave_sg+0x50/0xc4 > [ 2.065504] sci_dma_tx_work_fn+0xd8/0x1d4 > [ 2.065511] process_one_work+0x1dc/0x394 > [ 2.065515] worker_thread+0x21c/0x308 > [ 2.065520] kthread+0x118/0x128 > [ 2.065527] ret_from_fork+0x10/0x18 > [ 2.065530] ---[ end trace 75fc17d9000f1224 ]--- > > At first glance, it seems to give more details compared to: > rcar-dmac e7300000.dma-controller: rcar_dmac_prep_slave_sg: bad parameter: > len=1, id=19 Which would be followed by sh-sci e6e88000.serial: Failed preparing Tx DMA descriptor pointing to the sh-sci driver, right? The id=19 points to channel 0x13, i.e. SCIF2, according to arch/arm64/boot/dts/renesas/r8a7795.dtsi. > [1] https://patchwork.kernel.org/cover/11012981/ Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds