target/linux/generic/backport-6.1/729-15-v6.2-net-ethernet-mtk_wed-fix-sleep-while-atomic-in-mtk_w.patch

   1 From: Lorenzo Bianconi <lorenzo@kernel.org>
   2 Date: Thu, 1 Dec 2022 16:26:53 +0100
   3 Subject: [PATCH] net: ethernet: mtk_wed: fix sleep while atomic in
   4  mtk_wed_wo_queue_refill
   5
   6 In order to fix the following sleep while atomic bug always alloc pages
   7 with GFP_ATOMIC in mtk_wed_wo_queue_refill since page_frag_alloc runs in
   8 spin_lock critical section.
   9
  10 [    9.049719] Hardware name: MediaTek MT7986a RFB (DT)
  11 [    9.054665] Call trace:
  12 [    9.057096]  dump_backtrace+0x0/0x154
  13 [    9.060751]  show_stack+0x14/0x1c
  14 [    9.064052]  dump_stack_lvl+0x64/0x7c
  15 [    9.067702]  dump_stack+0x14/0x2c
  16 [    9.071001]  ___might_sleep+0xec/0x120
  17 [    9.074736]  __might_sleep+0x4c/0x9c
  18 [    9.078296]  __alloc_pages+0x184/0x2e4
  19 [    9.082030]  page_frag_alloc_align+0x98/0x1ac
  20 [    9.086369]  mtk_wed_wo_queue_refill+0x134/0x234
  21 [    9.090974]  mtk_wed_wo_init+0x174/0x2c0
  22 [    9.094881]  mtk_wed_attach+0x7c8/0x7e0
  23 [    9.098701]  mt7915_mmio_wed_init+0x1f0/0x3a0 [mt7915e]
  24 [    9.103940]  mt7915_pci_probe+0xec/0x3bc [mt7915e]
  25 [    9.108727]  pci_device_probe+0xac/0x13c
  26 [    9.112638]  really_probe.part.0+0x98/0x2f4
  27 [    9.116807]  __driver_probe_device+0x94/0x13c
  28 [    9.121147]  driver_probe_device+0x40/0x114
  29 [    9.125314]  __driver_attach+0x7c/0x180
  30 [    9.129133]  bus_for_each_dev+0x5c/0x90
  31 [    9.132953]  driver_attach+0x20/0x2c
  32 [    9.136513]  bus_add_driver+0x104/0x1fc
  33 [    9.140333]  driver_register+0x74/0x120
  34 [    9.144153]  __pci_register_driver+0x40/0x50
  35 [    9.148407]  mt7915_init+0x5c/0x1000 [mt7915e]
  36 [    9.152848]  do_one_initcall+0x40/0x25c
  37 [    9.156669]  do_init_module+0x44/0x230
  38 [    9.160403]  load_module+0x1f30/0x2750
  39 [    9.164135]  __do_sys_init_module+0x150/0x200
  40 [    9.168475]  __arm64_sys_init_module+0x18/0x20
  41 [    9.172901]  invoke_syscall.constprop.0+0x4c/0xe0
  42 [    9.177589]  do_el0_svc+0x48/0xe0
  43 [    9.180889]  el0_svc+0x14/0x50
  44 [    9.183929]  el0t_64_sync_handler+0x9c/0x120
  45 [    9.188183]  el0t_64_sync+0x158/0x15c
  46
  47 Fixes: 799684448e3e ("net: ethernet: mtk_wed: introduce wed wo support")
  48 Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
  49 Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
  50 Link: https://lore.kernel.org/r/67ca94bdd3d9eaeb86e52b3050fbca0bcf7bb02f.1669908312.git.lorenzo@kernel.org
  51 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  52 ---
  53
  54 --- a/drivers/net/ethernet/mediatek/mtk_wed_wo.c
  55 +++ b/drivers/net/ethernet/mediatek/mtk_wed_wo.c
  56 @@ -133,17 +133,18 @@ mtk_wed_wo_dequeue(struct mtk_wed_wo *wo
  57
  58  static int
  59  mtk_wed_wo_queue_refill(struct mtk_wed_wo *wo, struct mtk_wed_wo_queue *q,
  60 -                       gfp_t gfp, bool rx)
  61 +                       bool rx)
  62  {
  63         enum dma_data_direction dir = rx ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
  64         int n_buf = 0;
  65
  66         spin_lock_bh(&q->lock);
  67         while (q->queued < q->n_desc) {
  68 -               void *buf = page_frag_alloc(&q->cache, q->buf_size, gfp);
  69                 struct mtk_wed_wo_queue_entry *entry;
  70                 dma_addr_t addr;
  71 +               void *buf;
  72
  73 +               buf = page_frag_alloc(&q->cache, q->buf_size, GFP_ATOMIC);
  74                 if (!buf)
  75                         break;
  76
  77 @@ -215,7 +216,7 @@ mtk_wed_wo_rx_run_queue(struct mtk_wed_w
  78                         mtk_wed_mcu_rx_unsolicited_event(wo, skb);
  79         }
  80
  81 -       if (mtk_wed_wo_queue_refill(wo, q, GFP_ATOMIC, true)) {
  82 +       if (mtk_wed_wo_queue_refill(wo, q, true)) {
  83                 u32 index = (q->head - 1) % q->n_desc;
  84
  85                 mtk_wed_wo_queue_kick(wo, q, index);
  86 @@ -432,7 +433,7 @@ mtk_wed_wo_hardware_init(struct mtk_wed_
  87         if (ret)
  88                 goto error;
  89
  90 -       mtk_wed_wo_queue_refill(wo, &wo->q_tx, GFP_KERNEL, false);
  91 +       mtk_wed_wo_queue_refill(wo, &wo->q_tx, false);
  92         mtk_wed_wo_queue_reset(wo, &wo->q_tx);
  93
  94         regs.desc_base = MTK_WED_WO_CCIF_DUMMY5;
  95 @@ -446,7 +447,7 @@ mtk_wed_wo_hardware_init(struct mtk_wed_
  96         if (ret)
  97                 goto error;
  98
  99 -       mtk_wed_wo_queue_refill(wo, &wo->q_rx, GFP_KERNEL, true);
 100 +       mtk_wed_wo_queue_refill(wo, &wo->q_rx, true);
 101         mtk_wed_wo_queue_reset(wo, &wo->q_rx);
 102
 103         /* rx queue irqmask */