Arend, >Also I am not sure if the broken-sg-support is still needed. We added that for omap_hsmmc, but that has since changed to scatter-gather emulation so it might not be needed anymore. I can confirm it doesn't impact wifi performance in case of rk3288+ap6335. But I still have to set settings->bus.sdio.sd_head_align = 4 and settings->bus.sdio.sd_sgentry_align = 512, otherwise brcmf_sdiod_sglist_rw fails: 974.888452] net_ratelimit: 8 callbacks suppressed [ 974.888457] brcmfmac: brcmf_sdiod_sglist_rw: CMD53 sg block read failed -84 [ 974.901527] brcmfmac: brcmf_sdio_rxglom: glom read of 6144 bytes failed: -5 [ 974.910248] brcmfmac: brcmf_sdio_rxfail: abort command, terminate frame [ 975.018041] brcmfmac: brcmf_sdiod_sglist_rw: CMD53 sg block read failed -84 [ 975.025833] brcmfmac: brcmf_sdio_rxglom: glom read of 6144 bytes failed: -5 [ 975.033634] brcmfmac: brcmf_sdio_rxfail: abort command, terminate frame [ 975.033924] dwmmc_rockchip ff0d0000.dwmmc: Unexpected command timeout, state 0 [ 975.049209] brcmfmac: brcmf_sdio_readframes: RXHEADER FAILED: -84 [ 975.056034] brcmfmac: brcmf_sdio_rxfail: abort command, terminate frame, send NAK [ 975.068367] brcmfmac: brcmf_sdio_hdparse: HW header length too long [ 975.075379] brcmfmac: brcmf_sdio_rxfail: terminate frame Regards, Alex On 20 March 2018 at 06:16, Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> wrote: > + Uffe > > On 3/19/2018 6:55 PM, Florian Fainelli wrote: >> >> On 03/19/2018 07:10 AM, Alexey Roslyakov wrote: >>> >>> Hi Arend, >>> I appreciate your response. In my opinion, it has nothing to do with >>> SDIO host, because it defines "quirks" in the driver itself. >> >> >> It is not clear to me from your patch series whether the problem is that: >> >> - the SDIO device has a specific alignment requirements, which would be >> either a SDIO device driver limitation/issue or maybe the underlying >> hardware device/firmware requiring that >> >> - the SDIO host controller used is not capable of coping nicely with >> these said limitations >> >> It seems to me like what you are doing here is a) applicable to possibly >> more SDIO devices and host combinations, and b) should likely be done at >> the layer between the host and device, such that it is available to more >> combinations. > > > Indeed. That was my thought exactly and I can not imagine Uffe would push > back on that reasoning. > >>> If I get it right, you mean something like this: >>> >>> mmc3: mmc@1c12000 { >>> ... >>> broken-sg-support; >>> sd-head-align = 4; >>> sd-sgentry-align = 512; >>> >>> brcmf: wifi@1 { >>> ... >>> }; >>> }; >>> >>> Where dt: bindings documentation for these entries should reside? >>> In generic MMC bindings? Well, this is the very special case and >>> mmc-linux maintainer will unlikely to accept these changes. >>> Also, extra kernel code modification might be required. It could make >>> quite trivial change much more complex. >> >> >> If the MMC maintainers are not copied on this patch series, it will >> likely be hard for them to identify this patch series and chime in... > > > The main question is whether this is indeed a "very special case" as Alexey > claims it to be or that it is likely to be applicable to other device and > host combinations as you are suggesting. > > If these properties are imposed by the host or host controller it would make > sense to have these in the mmc bindings. > >>> >>>> Also I am not sure if the broken-sg-support is still needed. We added >>>> that for omap_hsmmc, but that has since changed to scatter-gather emulation >>>> so it might not be needed anymore. >>> >>> >>> I've experienced the problem with rk3288 (dw-mmc host) and sdio >>> settings like above solved it. >>> Frankly, I haven't investigated any deeper which one of the settings >>> helped in my case yet... >>> I will try to get rid of broken-sg-support first and let you know if >>> it does make any difference. > > > Are you using some chromebook. I have some lying around here so I could also > look into it. What broadcom chipset do you have? > > Regards, > Arend > > >>> All the best, >>> Alex. >>> >>> On 19 March 2018 at 16:31, Arend van Spriel >>> <arend.vanspriel@xxxxxxxxxxxx> wrote: >>>> >>>> On 3/19/2018 2:40 AM, Alexey Roslyakov wrote: >>>>> >>>>> >>>>> In case if the host has higher align requirements for SG items, allow >>>>> setting device-specific aligns for scatterlist items. >>>>> >>>>> Signed-off-by: Alexey Roslyakov <alexey.roslyakov@xxxxxxxxx> >>>>> --- >>>>> Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt >>>>> | 5 >>>>> +++++ >>>>> 1 file changed, 5 insertions(+) >>>>> >>>>> diff --git >>>>> a/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt >>>>> b/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt >>>>> index 86602f264dce..187b8c1b52a7 100644 >>>>> --- >>>>> a/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt >>>>> +++ >>>>> b/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt >>>>> @@ -17,6 +17,11 @@ Optional properties: >>>>> When not specified the device will use in-band SDIO >>>>> interrupts. >>>>> - interrupt-names : name of the out-of-band interrupt, which must >>>>> be >>>>> set >>>>> to "host-wake". >>>>> + - brcm,broken-sg-support : boolean flag to indicate that the SDIO >>>>> host >>>>> + controller has higher align requirement than 32 bytes for each >>>>> + scatterlist item. >>>>> + - brcm,sd-head-align : alignment requirement for start of data >>>>> buffer. >>>>> + - brcm,sd-sgentry-align : length alignment requirement for each sg >>>>> entry. >>>> >>>> >>>> >>>> Hi Alexey, >>>> >>>> Thanks for the patch. However, the problem with these is that they are >>>> characterizing the host controller and not the wireless device. So from >>>> device tree perspective , which is to describe the hardware, these >>>> properties should be SDIO host controller properties. Also I am not sure >>>> if >>>> the broken-sg-support is still needed. We added that for omap_hsmmc, but >>>> that has since changed to scatter-gather emulation so it might not be >>>> needed >>>> anymore. >>>> >>>> Regards, >>>> Arend >>> >>> >>> >>> >> >> > -- With best regards, Alexey Roslyakov Email: alexey.roslyakov@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html