On 10 July 2015 at 17:14, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Some sdio wifi modules have not been working reliable with the sunxi-mmc
> host code. This turns out to be caused by it starting new commands while
> the card signals that it is still busy processing a previous command.
Which are those commands? Or more interesting, which response types do
these commands expect?
I don't think this is a sunxi specific issue, I have seen similar
issues for other host controllers.
I am thinking that perhaps this should be managed by the mmc core
instead of local hacks to sunxi. Potentially we could make the core to
invoke the already existing host_ops->card_busy() callback when
needed...
Within this context, could I ask whether you controller supports IRQ
based HW-busy detection? Or you need polling of the status register?
>
> This commit fixes this, thereby fixing the wifi reliability issues on
> the Cubietruck and other sunxi boards using sdio wifi.
>
> Reported-by: Eugene K <sigintmailru@xxxxxxxxx>
> Suggested-by: Eugene K <sigintmailru@xxxxxxxxx>
> Cc: Eugene K <sigintmailru@xxxxxxxxx>
> Cc: Arend van Spriel <arend@xxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> -Properly accredit Eugene K for coming up with the fix for this
> ---
> drivers/mmc/host/sunxi-mmc.c | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
> index 4d3e1ff..daa90b7 100644
> --- a/drivers/mmc/host/sunxi-mmc.c
> +++ b/drivers/mmc/host/sunxi-mmc.c
> @@ -289,6 +289,24 @@ static int sunxi_mmc_init_host(struct mmc_host *mmc)
> return 0;
> }
>
> +/* Wait for card to report ready before starting a new cmd */
> +static int sunxi_mmc_wait_card_ready(struct sunxi_mmc_host *host)
> +{
> + unsigned long expire = jiffies + msecs_to_jiffies(500);
> + u32 rval;
> +
> + do {
> + rval = mmc_readl(host, REG_STAS);
> + } while (time_before(jiffies, expire) && (rval & SDXC_CARD_DATA_BUSY));
> +
> + if (rval & SDXC_CARD_DATA_BUSY) {
> + dev_err(mmc_dev(host->mmc), "Error R1 ready timeout\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> static void sunxi_mmc_init_idma_des(struct sunxi_mmc_host *host,
> struct mmc_data *data)
> {
> @@ -383,6 +401,8 @@ static void sunxi_mmc_send_manual_stop(struct sunxi_mmc_host *host,
> u32 arg, cmd_val, ri;
> unsigned long expire = jiffies + msecs_to_jiffies(1000);
>
> + sunxi_mmc_wait_card_ready(host);
> +
> cmd_val = SDXC_START | SDXC_RESP_EXPIRE |
> SDXC_STOP_ABORT_CMD | SDXC_CHECK_RESPONSE_CRC;
>
> @@ -597,6 +617,11 @@ static int sunxi_mmc_oclk_onoff(struct sunxi_mmc_host *host, u32 oclk_en)
> {
> unsigned long expire = jiffies + msecs_to_jiffies(250);
> u32 rval;
> + int ret;
> +
> + ret = sunxi_mmc_wait_card_ready(host);
> + if (ret)
> + return ret;
>
> rval = mmc_readl(host, REG_CLKCR);
> rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
> @@ -785,6 +810,13 @@ static void sunxi_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> return;
> }
>
> + ret = sunxi_mmc_wait_card_ready(host);
> + if (ret) {
> + mrq->cmd->error = ret;
> + mmc_request_done(mmc, mrq);
> + return;
> + }
> +
> if (data) {
> ret = sunxi_mmc_map_dma(host, data);
> if (ret < 0) {
> --
> 2.4.3
>
Kind regards
Uffe
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