Hi Niklas,
On 2.12.18 г. 1:50 ч., Niklas Cassel wrote:
On Wed, Nov 21, 2018 at 07:24:53PM +0200, Stanimir Varbanov wrote:
Hi,
On 11/14/18 12:57 AM, Marc Zyngier wrote:
It recently came to light that the Designware PCIe driver is rather
broken in the way it handles MSI[1]:
- It masks interrupt by disabling them, meaning that MSIs generated
during the masked window are simply lost. Oops.
- Acking of the currently pending MSI is done outside of the interrupt
flow, getting moved around randomly and ultimately breaking the
driver. Not great.
This series attempts to address this by switching to using the MASK
register for masking interrupts (!), and move the ack into the
appropriate callback, giving it a fixed place in the MSI handling
flow.
Note that this is only compile-tested on my arm64 laptop, as I'm
travelling and do not have the required HW to test it anyway. I'd
welcome both review and testing by the interested parties (dwc
maintainer and users affected by existing bugs).
Thanks,
M.
[1] https://patchwork.kernel.org/patch/10657987/
Marc Zyngier (3):
PCI: designware: Use interrupt masking instead of disabling
PCI: designware: Take lock when ACKing an interrupt
PCI: designware: Move interrupt acking into the proper callback
.../pci/controller/dwc/pcie-designware-host.c | 22 ++++++++++++-------
1 file changed, 14 insertions(+), 8 deletions(-)
for pcie-qcom:
Tested-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx>
Hello PCI folks,
Since this is a real bug, we should try get a couple of Tested-by tags
before it's too late.
It would be nice if v4.20 was released without broken MSIs in this driver.
Personally I get confused just by looking at this mail thread.
I see 3 patches from Marc and a fix-up from Marc, but I also see
a patch from Gustavo, and another patch from Trent.
Is seems like Lorenzo has a branch with Marc's 3 patches + Marc's fix-up
folded in here:
https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/log/?h=test%2Fpci-dwc-msi
Perhaps it would be a good idea to send a V2, with proper Fixes-tags,
just so that people would know what to test, so that we can start getting
those Tested-by tags.
Stan, may I ask exactly what patches you tested?
I tested Lorenzo's branch above ^^^.
regards,
Stan
