From mboxrd@z Thu Jan 1 00:00:00 1970 From: l.stach@pengutronix.de (Lucas Stach) Date: Mon, 09 Oct 2017 14:22:51 +0200 Subject: [PATCH 0/3] DWC host without MSI controller In-Reply-To: References: <20170828142307.30061-1-l.stach@pengutronix.de> Message-ID: <1507551771.2745.2.camel@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Fabio, Am Montag, den 09.10.2017, 09:14 -0300 schrieb Fabio Estevam: > Hi Bjorn, > > On Mon, Aug 28, 2017 at 1:59 PM, Tim Harvey > wrote: > > On Mon, Aug 28, 2017 at 7:23 AM, Lucas Stach > e> wrote: > > > Hi all, > > > > > > this small series tries to fix/workaround a serious design flaw > > > of the DWC PCIe > > > host controller: it is unable to work with both legacy and MSI > > > IRQs enabled at > > > the same time. As soon as the first MSI is enabled in the DWC MSI > > > controller, > > > the host stops forwarding legacy IRQs. > > > > > > If the MSI controller is present, MSIs will be used for the PCIe > > > port services > > > IRQs, leaving endpoint devices which don't support MSIs unable to > > > raise IRQs. > > > It is only safe to enable the MSI controller if it is validated > > > that all PCIe > > > devices and drivers in the system support working MSIs. As most > > > devices > > > support falling back to using legacy PCIe IRQs if MSI support is > > > missing it is > > > much safer to disable the MSI by default and only enable it on > > > validated > > > systems. > > > > > > Feedback welcome. > > > > > > Regards, > > > Lucas > > > > > > Lucas Stach (3): > > > ? PCI: designware: only register MSI controller when MSI irq line > > > is > > > ????valid > > > ? PCI: imx6: allow MSI irq to be absent > > > ? ARM: dts: imx6qdl: remove MSI irq line > > > > > > ?.../devicetree/bindings/pci/fsl,imx6q-pcie.txt?????|??8 ++++---- > > > ?arch/arm/boot/dts/imx6qdl.dtsi?????????????????????|??2 -- > > > ?drivers/pci/dwc/pci-imx6.c?????????????????????????| 23 > > > +++++++++++----------- > > > ?drivers/pci/dwc/pcie-designware-host.c?????????????|??4 ++-- > > > ?4 files changed, 17 insertions(+), 20 deletions(-) > > > > > > > Lucas, > > > > Thank you for following up on this! > > > > I tested it with and without the third patch that removes msi from > > the > > dt thus with both an ath9k 802.11 device which only supports legacy > > interrupts and a Marvell sky2 device which supports msi as well as > > legacy interrupts and it works as expected: > > ?- without msi enabled in dts (default): both sky2 and ath9k work > > ?- with msi enabled in dt: sky2 works ath9k does not > > > > Tested-by: Tim Harvey > > Any comments about this series? Bjorn already commented on the series and I'm trying free up a slot to address the feedback. Regards, Lucas