Am Dienstag, den 16.09.2014, 09:30 +0800 schrieb Yijing Wang:

On 2014/9/15 22:00, Lucas Stach wrote:

quoted

Am Freitag, den 05.09.2014, 18:09 +0800 schrieb Yijing Wang:

quoted

Currently, pcie-designware, pcie-rcar, pci-tegra drivers
use irq chip_data to save the msi_chip pointer. They
already call irq_set_chip_data() in their own MSI irq map
functions. So irq_set_chip_data() in arch_setup_msi_irq()
is useless.

Signed-off-by: Yijing Wang <redacted>
---
 drivers/pci/msi.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index f6cb317..d547f7f 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c

@@ -41,8 +41,6 @@ int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 	if (err < 0)
 		return err;
 
-	irq_set_chip_data(desc->irq, chip);
-
 	return 0;
 }
 

arch_teardown_msi_irq() expects to find the msi_chip in the irq
chip_data field. As this means drivers don't have any reasonable other
possibility to stuff things into this field, I think it would make sense
to do the cleanup the other way around: keep the irq_set_chip_data
arch_setup_msi_irq() and rip it out of the individual drivers.

Hi Lucas, thanks for your review and comments!
irq_set_chip_data() should not be placed in MSI core functions, because other arch like x86,
use irq_data->chip_data to stores irq_cfg. So how to set the chip_data is arch dependent.
And this series is mainly to use MSI chip framework in all platforms.
Currently, only ARM platform MSI drivers use the chip_data to store msi_chip, and the drivers call
irq_set_chip_data() in their driver already. So I thought we should clean up it in MSI core code.

Okay I see your point, so the cleanup done this way is okay.

But then this still introduces a problem: arch_teardown_msi_irq()
expects to find the msi_chip in the chip_data field, which is okay for
all ARM PCI host drivers, but not for other arch MSI chips.

You fix this by completely removing arch_teardown_msi_irq() at the end
of the series, but this still has the potential to introduce issues for
other arches than ARM within the series. So this patch should include a
change to replace the line

struct msi_chip *chip = irq_get_chip_data(irq);

with something that doesn't rely on the msi_chip being in the irq
chip_data field.

Regards,
Lucas

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