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Re: [PATCH v3 2/3] pci: Honour wmask when resetting PCI_INTERRUPT_LINE
From: |
Michael S. Tsirkin |
Subject: |
Re: [PATCH v3 2/3] pci: Honour wmask when resetting PCI_INTERRUPT_LINE |
Date: |
Mon, 9 Mar 2020 16:39:19 -0400 |
On Mon, Mar 09, 2020 at 08:18:13PM +0100, BALATON Zoltan wrote:
> The pci_do_device_reset() function (called from pci_device_reset)
> clears the PCI_INTERRUPT_LINE config reg of devices on the bus but did
> this without taking wmask into account. We'll have a device model now
> that needs to set a constant value for this reg and this patch allows
> to do that without additional workaround in device emulation to
> reverse the effect of this PCI bus reset function.
>
> Suggested-by: Mark Cave-Ayland <address@hidden>
> Signed-off-by: BALATON Zoltan <address@hidden>
> ---
> hw/pci/pci.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index e1ed6677e1..d07e4ed9de 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -302,8 +302,10 @@ static void pci_do_device_reset(PCIDevice *dev)
> pci_word_test_and_clear_mask(dev->config + PCI_STATUS,
> pci_get_word(dev->wmask + PCI_STATUS) |
> pci_get_word(dev->w1cmask + PCI_STATUS));
> + pci_word_test_and_clear_mask(dev->config + PCI_INTERRUPT_LINE,
> + pci_get_word(dev->wmask + PCI_INTERRUPT_LINE) |
> + pci_get_word(dev->w1cmask +
> PCI_INTERRUPT_LINE));
PCI spec says:
Interrupt Line
The Interrupt Line register is an eight-bit register used to communicate
interrupt line routing
information.
I don't see how it makes sense to access it as a word.
> dev->config[PCI_CACHE_LINE_SIZE] = 0x0;
> - dev->config[PCI_INTERRUPT_LINE] = 0x0;
> for (r = 0; r < PCI_NUM_REGIONS; ++r) {
> PCIIORegion *region = &dev->io_regions[r];
> if (!region->size) {
Please add comments here explaining that some devices
make PCI_INTERRUPT_LINE read-only.
> --
> 2.21.1
>
>
Re: [PATCH v3 0/3] Implement "non 100% native mode" in via-ide, no-reply, 2020/03/09
Re: [PATCH v3 0/3] Implement "non 100% native mode" in via-ide, Mark Cave-Ayland, 2020/03/10