target/linux/mvebu/patches-4.9/110-pxa3xxx_revert_irq_thread.patch

   1 Revert "mtd: pxa3xx-nand: handle PIO in threaded interrupt"
   2
   3 This reverts commit 24542257a3b987025d4b998ec2d15e556c98ad3f
   4 This upstream change has been causing spurious timeouts on accesses
   5 to the NAND flash if something else on the system is causing
   6 significant latency.
   7
   8 Nothing guarantees that the thread will run in time, so the
   9 usual timeout is unreliable.
  10
  11 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  12
  13 --- a/drivers/mtd/nand/pxa3xx_nand.c
  14 +++ b/drivers/mtd/nand/pxa3xx_nand.c
  15 @@ -791,24 +791,11 @@ static void start_data_dma(struct pxa3xx
  16                 __func__, direction, info->dma_cookie, info->sg.length);
  17  }
  18
  19 -static irqreturn_t pxa3xx_nand_irq_thread(int irq, void *data)
  20 -{
  21 -       struct pxa3xx_nand_info *info = data;
  22 -
  23 -       handle_data_pio(info);
  24 -
  25 -       info->state = STATE_CMD_DONE;
  26 -       nand_writel(info, NDSR, NDSR_WRDREQ | NDSR_RDDREQ);
  27 -
  28 -       return IRQ_HANDLED;
  29 -}
  30 -
  31  static irqreturn_t pxa3xx_nand_irq(int irq, void *devid)
  32  {
  33         struct pxa3xx_nand_info *info = devid;
  34         unsigned int status, is_completed = 0, is_ready = 0;
  35         unsigned int ready, cmd_done;
  36 -       irqreturn_t ret = IRQ_HANDLED;
  37
  38         if (info->cs == 0) {
  39                 ready           = NDSR_FLASH_RDY;
  40 @@ -850,8 +837,7 @@ static irqreturn_t pxa3xx_nand_irq(int i
  41                 } else {
  42                         info->state = (status & NDSR_RDDREQ) ?
  43                                       STATE_PIO_READING : STATE_PIO_WRITING;
  44 -                       ret = IRQ_WAKE_THREAD;
  45 -                       goto NORMAL_IRQ_EXIT;
  46 +                       handle_data_pio(info);
  47                 }
  48         }
  49         if (status & cmd_done) {
  50 @@ -896,7 +882,7 @@ static irqreturn_t pxa3xx_nand_irq(int i
  51         if (is_ready)
  52                 complete(&info->dev_ready);
  53  NORMAL_IRQ_EXIT:
  54 -       return ret;
  55 +       return IRQ_HANDLED;
  56  }
  57
  58  static inline int is_buf_blank(uint8_t *buf, size_t len)
  59 @@ -1857,9 +1843,7 @@ static int alloc_nand_resource(struct pl
  60         /* initialize all interrupts to be disabled */
  61         disable_int(info, NDSR_MASK);
  62
  63 -       ret = request_threaded_irq(irq, pxa3xx_nand_irq,
  64 -                                  pxa3xx_nand_irq_thread, IRQF_ONESHOT,
  65 -                                  pdev->name, info);
  66 +       ret = request_irq(irq, pxa3xx_nand_irq, 0, pdev->name, info);
  67         if (ret < 0) {
  68                 dev_err(&pdev->dev, "failed to request IRQ\n");
  69                 goto fail_free_buf;