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SubjectRe: [PATCH 1/2] mmc: core: Improve marking broken HPI through devicetree
From
On 19 April 2016 at 09:12, Olliver Schinagl <oliver@schinagl.nl> wrote:
> In patch 81f8a7be66 Hans de Goede added a patch to allow marking an mmc
> device as to having an broken HPI implementation. After talking some
> with Hans, we now think it is actually the mmc controller that can be
> broken and not support broken HPI's.

I don't want us to invent a DT binding for something you *think* is a
HW controller issue.

Have you really excluded that this isn't a software issue? Me
personally haven't been using HPI that much so I can't really tell
about the code robustness from the mmc core (mmc protocol point of
view).

Kind regards
Uffe

>
> This patch adds a new capability, mmc-broken-hpi, which allows us to
> mark a broken hpi implementation on the host level.
>
> Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
> ---
> drivers/mmc/core/host.c | 2 ++
> drivers/mmc/core/mmc.c | 2 +-
> include/linux/mmc/host.h | 1 +
> 3 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 6e4c55a..9b63b36 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -270,6 +270,8 @@ int mmc_of_parse(struct mmc_host *host)
> host->caps |= MMC_CAP_HW_RESET;
> if (of_property_read_bool(np, "cap-sdio-irq"))
> host->caps |= MMC_CAP_SDIO_IRQ;
> + if (of_property_read_bool(np, "mmc-broken-hpi"))
> + host->caps |= MMC_CAP_BROKEN_HPI;
> if (of_property_read_bool(np, "full-pwr-cycle"))
> host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
> if (of_property_read_bool(np, "keep-power-in-suspend"))
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 4dbe3df..9a19562 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1592,7 +1592,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> /*
> * Enable HPI feature (if supported)
> */
> - if (card->ext_csd.hpi) {
> + if (card->ext_csd.hpi && !(host->caps & MMC_CAP_BROKEN_HPI)) {
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> EXT_CSD_HPI_MGMT, 1,
> card->ext_csd.generic_cmd6_time);
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 8dd4d29..20f758e 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -264,6 +264,7 @@ struct mmc_host {
> #define MMC_CAP_DRIVER_TYPE_A (1 << 23) /* Host supports Driver Type A */
> #define MMC_CAP_DRIVER_TYPE_C (1 << 24) /* Host supports Driver Type C */
> #define MMC_CAP_DRIVER_TYPE_D (1 << 25) /* Host supports Driver Type D */
> +#define MMC_CAP_BROKEN_HPI (1 << 29) /* Host support for HPI is broken */
> #define MMC_CAP_CMD23 (1 << 30) /* CMD23 supported. */
> #define MMC_CAP_HW_RESET (1 << 31) /* Hardware reset */
>
> --
> 2.8.0.rc3
>

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