Re: [PATCH v4] mmc: mmci: Support odd block sizes for ux500v2 and qcom variant

[Ulf Hansson <ulf.hansson@linaro.org>]

On Wed, 11 Dec 2019 at 09:47, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Mon, 2 Dec 2019 at 23:28, Linus Walleij <linus.walleij@linaro.org> wrote:
> >
> > For the ux500v2 variant of the PL18x block, odd block sizes
> > are supported. This is necessary to support some SDIO
> > transfers. This also affects the QCOM MMCI variant and the
> > ST micro variant.
> >
> > For Ux500 an additional quirk only allowing DMA on blocks
> > that are a power of two is needed. This might be a bug in
> > the DMA engine (DMA40) or the MMCI or in the interconnect,
> > but the most likely is the MMCI, as transfers of these
> > sizes work fine for other devices using the same DMA
> > engine. DMA works fine also with SDIO as long as the
> > blocksize is a power of 2.
> >
> > This patch has proven necessary for enabling SDIO for WLAN on
> > PostmarketOS-based Ux500 platforms.
> >
> > What we managed to test in practice is Broadcom WiFi over
> > SDIO on the Ux500 based Samsung GT-I8190 and GT-S7710.
> > This WiFi chip, BCM4334 works fine after the patch.
> >
> > Before this patch:
> >
> > brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac4334-sdio
> >           for chip BCM4334/3
> > mmci-pl18x 80118000.sdi1_per2: unsupported block size (60 bytes)
> > brcmfmac: brcmf_sdiod_ramrw: membytes transfer failed
> > brcmfmac: brcmf_sdio_download_code_file: error -22 on writing
> >           434236 membytes at 0x00000000
> > brcmfmac: brcmf_sdio_download_firmware: dongle image file download
> >           failed
> >
> > After this patch:
> >
> > brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4334/3 wl0:
> >           Nov 21 2012 00:21:28 version 6.10.58.813 (B2) FWID 01-0
> >
> > Bringing up networks, discovering networks with "iw dev wlan0 scan"
> > and connecting works fine from this point.
> >
> > This patch is inspired by Ulf Hansson's patch
> > http://www.spinics.net/lists/linux-mmc/msg12160.html
> >
> > As the DMA engines on these platforms may now get block sizes
> > they were not used to before, make sure to also respect if
> > the DMA engine says "no" to a transfer.
> >
> > Make a drive-by fix for datactrl_blocksz, misspelled.
>
> Alright, I think this approach makes sense.
>
> Especially, trying to make some changes in mmci_pio_read|write() that
> we can trigger/test doesn't make sense.

/s/can/can't

[...]

Kind regards
Uffe