Re: [PATCH v6] mmc: mmci: Support odd block sizes for ux500v2 and qcom variant

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

On Tue, 17 Dec 2019 at 15:39, 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.
>
> Cc: Ludovic Barre <ludovic.barre@st.com>
> Cc: Brian Masney <masneyb@onstation.org>
> Cc: Stephan Gerhold <stephan@gerhold.net>
> Cc: Niklas Cassel <niklas.cassel@linaro.org>
> Cc: Russell King <rmk+kernel@armlinux.org.uk>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Applied for next (the conflict was trivial for me to fix), thanks!

Kind regards
Uffe


> ---
> ChangeLog v5->v6:
> - Actually commit the changes I have in my tree
>   and resend...  We now have the config members
>   datactrl_any_blocksz and dma_power_of_2 as intended.
> ChangeLog v4->v5:
> - Rename variant members as Ulf want them.
> ChangeLog v3->v4:
> - Rewrite the patch to accept odd packages but only
>   let power of two packages pass on to the DMA.
> - Drop the patches disallowing DMA not divisible by 4:
>   this doesn't work. Instead just push the whole
>   power of two criteria down to the DMA submission
>   phase.
> - Drop the patch handling odd sglist offsets and
>   passing of page boundaries in SG buffers when
>   using PIO: it just doesn't happen in practice, we
>   don't know why, but likely because all packets are
>   small.
> ChangeLog v2->v3:
> - Repost with the inclusion of other patches.
> ChangeLog v1->v2:
> - Specify odd blocksize field to 1 bit (:1)
> - Specify that STMMC supports odd block sizes
> - Collect Stephan's test tag
> ---
>  drivers/mmc/host/mmci.c | 34 ++++++++++++++++++++++++++++++----
>  drivers/mmc/host/mmci.h |  8 +++++++-
>  2 files changed, 37 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index c37e70dbe250..7e4bc9124efd 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -168,6 +168,8 @@ static struct variant_data variant_ux500 = {
>         .cmdreg_srsp            = MCI_CPSM_RESPONSE,
>         .datalength_bits        = 24,
>         .datactrl_blocksz       = 11,
> +       .datactrl_any_blocksz   = true,
> +       .dma_power_of_2         = true,
>         .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
>         .st_sdio                = true,
>         .st_clkdiv              = true,
> @@ -201,6 +203,8 @@ static struct variant_data variant_ux500v2 = {
>         .datactrl_mask_ddrmode  = MCI_DPSM_ST_DDRMODE,
>         .datalength_bits        = 24,
>         .datactrl_blocksz       = 11,
> +       .datactrl_any_blocksz   = true,
> +       .dma_power_of_2         = true,
>         .datactrl_mask_sdio     = MCI_DPSM_ST_SDIOEN,
>         .st_sdio                = true,
>         .st_clkdiv              = true,
> @@ -260,6 +264,7 @@ static struct variant_data variant_stm32_sdmmc = {
>         .datacnt_useless        = true,
>         .datalength_bits        = 25,
>         .datactrl_blocksz       = 14,
> +       .datactrl_any_blocksz   = true,
>         .stm32_idmabsize_mask   = GENMASK(12, 5),
>         .init                   = sdmmc_variant_init,
>  };
> @@ -279,6 +284,7 @@ static struct variant_data variant_qcom = {
>         .data_cmd_enable        = MCI_CPSM_QCOM_DATCMD,
>         .datalength_bits        = 24,
>         .datactrl_blocksz       = 11,
> +       .datactrl_any_blocksz   = true,
>         .pwrreg_powerup         = MCI_PWR_UP,
>         .f_max                  = 208000000,
>         .explicit_mclk_control  = true,
> @@ -447,10 +453,11 @@ void mmci_dma_setup(struct mmci_host *host)
>  static int mmci_validate_data(struct mmci_host *host,
>                               struct mmc_data *data)
>  {
> +       struct variant_data *variant = host->variant;
> +
>         if (!data)
>                 return 0;
> -
> -       if (!is_power_of_2(data->blksz)) {
> +       if (!is_power_of_2(data->blksz) && !variant->datactrl_any_blocksz) {
>                 dev_err(mmc_dev(host->mmc),
>                         "unsupported block size (%d bytes)\n", data->blksz);
>                 return -EINVAL;
> @@ -515,7 +522,9 @@ int mmci_dma_start(struct mmci_host *host, unsigned int datactrl)
>                  "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
>                  data->sg_len, data->blksz, data->blocks, data->flags);
>
> -       host->ops->dma_start(host, &datactrl);
> +       ret = host->ops->dma_start(host, &datactrl);
> +       if (ret)
> +               return ret;
>
>         /* Trigger the DMA transfer */
>         mmci_write_datactrlreg(host, datactrl);
> @@ -822,6 +831,18 @@ static int _mmci_dmae_prep_data(struct mmci_host *host, struct mmc_data *data,
>         if (data->blksz * data->blocks <= variant->fifosize)
>                 return -EINVAL;
>
> +       /*
> +        * This is necessary to get SDIO working on the Ux500. We do not yet
> +        * know if this is a bug in:
> +        * - The Ux500 DMA controller (DMA40)
> +        * - The MMCI DMA interface on the Ux500
> +        * some power of two blocks (such as 64 bytes) are sent regularly
> +        * during SDIO traffic and those work fine so for these we enable DMA
> +        * transfers.
> +        */
> +       if (host->variant->dma_power_of_2 && !is_power_of_2(data->blksz))
> +               return -EINVAL;
> +
>         device = chan->device;
>         nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len,
>                            mmc_get_dma_dir(data));
> @@ -872,9 +893,14 @@ int mmci_dmae_prep_data(struct mmci_host *host,
>  int mmci_dmae_start(struct mmci_host *host, unsigned int *datactrl)
>  {
>         struct mmci_dmae_priv *dmae = host->dma_priv;
> +       int ret;
>
>         host->dma_in_progress = true;
> -       dmaengine_submit(dmae->desc_current);
> +       ret = dma_submit_error(dmaengine_submit(dmae->desc_current));
> +       if (ret < 0) {
> +               host->dma_in_progress = false;
> +               return ret;
> +       }
>         dma_async_issue_pending(dmae->cur);
>
>         *datactrl |= MCI_DPSM_DMAENABLE;
> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> index 833236ecb31e..89ab73343cf3 100644
> --- a/drivers/mmc/host/mmci.h
> +++ b/drivers/mmc/host/mmci.h
> @@ -278,7 +278,11 @@ struct mmci_host;
>   * @stm32_clkdiv: true if using a STM32-specific clock divider algorithm
>   * @datactrl_mask_ddrmode: ddr mode mask in datactrl register.
>   * @datactrl_mask_sdio: SDIO enable mask in datactrl register
> - * @datactrl_blksz: block size in power of two
> + * @datactrl_blocksz: block size in power of two
> + * @datactrl_any_blocksz: true if block any block sizes are accepted by
> + *               hardware, such as with some SDIO traffic that send
> + *               odd packets.
> + * @dma_power_of_2: DMA only works with blocks that are a power of 2.
>   * @datactrl_first: true if data must be setup before send command
>   * @datacnt_useless: true if you could not use datacnt register to read
>   *                  remaining data
> @@ -323,6 +327,8 @@ struct variant_data {
>         unsigned int            datactrl_mask_ddrmode;
>         unsigned int            datactrl_mask_sdio;
>         unsigned int            datactrl_blocksz;
> +       u8                      datactrl_any_blocksz:1;
> +       u8                      dma_power_of_2:1;
>         u8                      datactrl_first:1;
>         u8                      datacnt_useless:1;
>         u8                      st_sdio:1;
> --
> 2.21.0
>