Re: [Qemu-devel] [PATCH 2/5] floppy: move dma setup + drive connect to fdctrl_init_common()

[Markus Armbruster <armbru@redhat.com>]

Gerd Hoffmann <kraxel@redhat.com> writes:

> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hw/fdc.c |   33 ++++++++++++---------------------
>  1 files changed, 12 insertions(+), 21 deletions(-)
>
> diff --git a/hw/fdc.c b/hw/fdc.c
> index ea3b8ac..537db66 100644
> --- a/hw/fdc.c
> +++ b/hw/fdc.c
> @@ -1842,23 +1842,14 @@ static void fdctrl_connect_drives(fdctrl_t *fdctrl)
>  
>  fdctrl_t *fdctrl_init_isa(DriveInfo **fds)
>  {
> -    fdctrl_t *fdctrl;
>      ISADevice *dev;
> -    int dma_chann = 2;
>  
>      dev = isa_create("isa-fdc");
>      qdev_prop_set_drive(&dev->qdev, "driveA", fds[0]);
>      qdev_prop_set_drive(&dev->qdev, "driveB", fds[1]);
>      if (qdev_init(&dev->qdev) != 0)
>          return NULL;
> -    fdctrl = &(DO_UPCAST(fdctrl_isabus_t, busdev, dev)->state);
> -
> -    fdctrl->dma_chann = dma_chann;
> -    DMA_register_channel(dma_chann, &fdctrl_transfer_handler, fdctrl);
> -
> -    fdctrl_connect_drives(fdctrl);
> -
> -    return fdctrl;
> +    return &(DO_UPCAST(fdctrl_isabus_t, busdev, dev)->state);

Redundant parenthesis.

>  }
>  
>  fdctrl_t *fdctrl_init_sysbus(qemu_irq irq, int dma_chann,
> @@ -1870,19 +1861,16 @@ fdctrl_t *fdctrl_init_sysbus(qemu_irq irq, int dma_chann,
>      fdctrl_sysbus_t *sys;
>  
>      dev = qdev_create(NULL, "sysbus-fdc");
> +    sys = DO_UPCAST(fdctrl_sysbus_t, busdev.qdev, dev);
> +    fdctrl = &sys->state;
> +    fdctrl->dma_chann = dma_chann; /* FIXME */

What needs to be fixed here?  Could that be explained in the comment?

>      qdev_prop_set_drive(dev, "driveA", fds[0]);
>      qdev_prop_set_drive(dev, "driveB", fds[1]);
>      if (qdev_init(dev) != 0)
>          return NULL;
> -    sys = DO_UPCAST(fdctrl_sysbus_t, busdev.qdev, dev);
> -    fdctrl = &sys->state;
>      sysbus_connect_irq(&sys->busdev, 0, irq);
>      sysbus_mmio_map(&sys->busdev, 0, mmio_base);
>  
> -    fdctrl->dma_chann = dma_chann;
> -    DMA_register_channel(dma_chann, &fdctrl_transfer_handler, fdctrl);
> -    fdctrl_connect_drives(fdctrl);
> -
>      return fdctrl;
>  }
>  
> @@ -1901,11 +1889,7 @@ fdctrl_t *sun4m_fdctrl_init (qemu_irq irq, target_phys_addr_t io_base,
>      fdctrl = &sys->state;
>      sysbus_connect_irq(&sys->busdev, 0, irq);
>      sysbus_mmio_map(&sys->busdev, 0, io_base);
> -    *fdc_tc = qdev_get_gpio_in(dev, 0);
> -
> -    fdctrl->dma_chann = -1;
> -
> -    fdctrl_connect_drives(fdctrl);
> +    *fdc_tc = qdev_get_gpio_in(dev, 0); /* FIXME */

Same question.

>  
>      return fdctrl;
>  }
> @@ -1937,6 +1921,10 @@ static int fdctrl_init_common(fdctrl_t *fdctrl)
>      fdctrl->config = FD_CONFIG_EIS | FD_CONFIG_EFIFO; /* Implicit seek, polling & FIFO enabled */
>      fdctrl->num_floppies = MAX_FD;
>  
> +    if (fdctrl->dma_chann != -1)
> +        DMA_register_channel(fdctrl->dma_chann, &fdctrl_transfer_handler, fdctrl);
> +    fdctrl_connect_drives(fdctrl);
> +
>      fdctrl_external_reset(fdctrl);
>      vmstate_register(-1, &vmstate_fdc, fdctrl);
>      qemu_register_reset(fdctrl_external_reset, fdctrl);
> @@ -1949,6 +1937,7 @@ static int isabus_fdc_init1(ISADevice *dev)
>      fdctrl_t *fdctrl = &isa->state;
>      int iobase = 0x3f0;
>      int isairq = 6;
> +    int dma_chann = 2;
>  
>      register_ioport_read(iobase + 0x01, 5, 1,
>                           &fdctrl_read_port, fdctrl);
> @@ -1959,6 +1948,7 @@ static int isabus_fdc_init1(ISADevice *dev)
>      register_ioport_write(iobase + 0x07, 1, 1,
>                            &fdctrl_write_port, fdctrl);
>      isa_init_irq(&isa->busdev, &fdctrl->irq, isairq);
> +    fdctrl->dma_chann = dma_chann;
>  
>      return fdctrl_init_common(fdctrl);
>  }
> @@ -1972,6 +1962,7 @@ static int sysbus_fdc_init1(SysBusDevice *dev)
>      sysbus_init_mmio(dev, 0x08, io);
>      sysbus_init_irq(dev, &fdctrl->irq);
>      qdev_init_gpio_in(&dev->qdev, fdctrl_handle_tc, 1);
> +    fdctrl->dma_chann = -1;
>  
>      return fdctrl_init_common(fdctrl);
>  }

Hmm, as far as I can see, initialization of fdctrl->dma_chann moved to
the qdev init() method for ISA and Sun4m, but not for sysbus.
Intentional?  If yes, what about explaining it in the code, or perhaps
the commit message?