Messages in this thread | | | Date | Wed, 10 Dec 2014 12:40:38 -0800 | From | Ray Jui <> | Subject | Re: [PATCH 2/4] PCI: iproc: Add Broadcom iProc PCIe driver |
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On 12/10/2014 12:26 PM, Hauke Mehrtens wrote: > On 12/10/2014 07:46 PM, Florian Fainelli wrote: >> 2014-12-10 8:46 GMT-08:00 Scott Branden <sbranden@broadcom.com>: >>> On 14-12-10 03:31 AM, Arnd Bergmann wrote: >>>> >>>> On Tuesday 09 December 2014 16:04:29 Ray Jui wrote: >>>>> >>>>> Add initial version of the Broadcom iProc PCIe driver. This driver >>>>> has been tested on NSP and Cygnus and is expected to work on all iProc >>>>> family of SoCs that deploys the same PCIe host controller >>>>> >>>>> The driver also supports MSI >>>>> >>>>> Signed-off-by: Ray Jui <rjui@broadcom.com> >>>>> Reviewed-by: Scott Branden <sbranden@broadcom.com> >>>> >>>> >>>> The driver looks suspiciously like the one that Hauke already submitted a >>>> while ago for bcm53xx. Please come up with a merged driver that works for >>>> both. >>> >>> Could you please be a little more specific. What driver did "Hauke already >>> submitted"? I do not see any driver in the kernel you are talking about. >> >> https://www.marc.info/?l=linux-pci&m=141547043110684&w=2 > > Yes it also looks similar to me. Your code also contains the same > comments as the driver used on Northstar (BCM5301X).Your driver has > some more features, but I just have access to the consumer SoC Northstar > where the PCIe controller is only used to connect some Broadcom Wifi > chips to the SoC. I do not know If this controller does not have these > features or the driver I used as a reference does not implement them. > Right, I wrote this driver based on some old Broadcom internal PCIe driver from a 3.6 kernel and might have copied some of the comments (especially in the check link function). The 3.6 driver is probably what you received?
> When I find some time I will try this driver on a Northstar device. I > think your driver is more advanced then the one I send to the mailing list. > Please do that. I tested this driver on Cygnus and one of my colleagues helped to test it on North Star Plus. We do expect the same driver to work on NorthStar as well.
> When you want to stay with pure device tree I will send a patch adding > additional support for registering to bcma. > What exactly is bcma? I guess I'll need to look into it in more details myself.
> Does your SoC also have a third PCIe controller which shares the PHY > with the USB 3 controller? No. Cygnus has only two PCIe controllers, each has its own dedicated PHY.
> > Why is this stuff in the iproc_pcie_check_link() function needed? I > think it is strange that the controller driver has to check if the > device is there and set the correct speed. When we do not check if the > card is there on BCM5301X the device stops working. > I need to check with our ASIC engineer on this. In theory we should be able to support hot plug eventually, but maybe not in the initial version of this driver.
>>>> Are you sure that iProc isn't based on the BCMA bus infrastructure after >>>> all? Even the physical address of your PCI host falls into the address >>>> range that is used for the internal BCMA bus on the other chips! >>> >>> BCMA seems to be for MIPS architectures. It seems to be quite specific to >>> those architectures using BCMA. I see no use of it in bcm53xx code? >> >> BCMA lives in its own directory in drivers/bcma/ and is not specific >> to MIPS actually. Older BCM47xx/BCM53xx MIPS-based SoCs traditionally >> started with a discoverable Silicon Sonics Backplane (drivers/ssb) and >> progressively migrated to BCMA (drivers/bcma), both subsystems offer a >> very similar bus/device/driver abstraction and discovery mechanism. > > With mainline kernel 3.18 you can boot Linux on a BCM5301X SoC and bcma > will find all the cores. > > Hauke >
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