On Fri, 27 Aug 2010, Chris Ball wrote:
> Hi,
>
> Any comments on this patch from the list?
Looks rather hackish to me. There should be a more elegant way to
achieve the same result. I have no time to look at it and propose an
alternative solution though.
>
> From: Bing Zhao <bzhao@xxxxxxxxxxx>
> Date: Wed, 21 Jul 2010 18:46:55 -0700
>
> Marvell 8686/8688 device will not respond to re-probe attemps
> in powered resume, if the card is in sleep mode.
> The added MMC_PM_SKIP_RESUME_PROBE flag is checked so that
> call to mmc_sdio_init_card() can be skipped.
>
> Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
> ---
> drivers/mmc/core/sdio.c | 18 +++++++++++++++---
> drivers/mmc/host/sdhci-pci.c | 3 ++-
> include/linux/mmc/pm.h | 1 +
> 3 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
> index bd2755e..dc03939 100644
> --- a/drivers/mmc/core/sdio.c
> +++ b/drivers/mmc/core/sdio.c
> @@ -606,15 +606,27 @@ static int mmc_sdio_suspend(struct mmc_host *host)
>
> static int mmc_sdio_resume(struct mmc_host *host)
> {
> - int i, err;
> + int i, err = 0;
>
> BUG_ON(!host);
> BUG_ON(!host->card);
>
> /* Basic card reinitialization. */
> mmc_claim_host(host);
> - err = mmc_sdio_init_card(host, host->ocr, host->card,
> - (host->pm_flags & MMC_PM_KEEP_POWER));
> +
> + /*
> + * For a powered resume, Marvell 8686/8688 device will not respond
> + * to re-initialization attemps if the card is in sleep mode.
> + * The MMC_PM_SKIP_RESUME_PROBE flag is added as a workaround here.
> + * This is a temporary measure until a fully thought-through
> + * solution is elaborated.
> + */
> + if (!(host->pm_flags & MMC_PM_KEEP_POWER) ||
> + !(host->pm_flags & MMC_PM_SKIP_RESUME_PROBE)) {
> + err = mmc_sdio_init_card(host, host->ocr, host->card,
> + host->pm_flags & MMC_PM_KEEP_POWER);
> + }
> +
> if (!err) {
> /* We may have switched to 1-bit mode during suspend. */
> err = sdio_enable_4bit_bus(host->card);
> diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
> index e021431..4f793f8 100644
> --- a/drivers/mmc/host/sdhci-pci.c
> +++ b/drivers/mmc/host/sdhci-pci.c
> @@ -703,7 +703,8 @@ static struct sdhci_pci_slot * __devinit sdhci_pci_probe_slot(
> goto unmap;
> }
>
> - host->mmc->pm_caps = MMC_PM_KEEP_POWER | MMC_PM_WAKE_SDIO_IRQ;
> + host->mmc->pm_caps = MMC_PM_KEEP_POWER | MMC_PM_WAKE_SDIO_IRQ
> + | MMC_PM_SKIP_RESUME_PROBE;
>
> ret = sdhci_add_host(host);
> if (ret)
> diff --git a/include/linux/mmc/pm.h b/include/linux/mmc/pm.h
> index d37aac4..7dbb630 100644
> --- a/include/linux/mmc/pm.h
> +++ b/include/linux/mmc/pm.h
> @@ -26,5 +26,6 @@ typedef unsigned int mmc_pm_flag_t;
>
> #define MMC_PM_KEEP_POWER (1 << 0) /* preserve card power during suspend */
> #define MMC_PM_WAKE_SDIO_IRQ (1 << 1) /* wake up host system on SDIO IRQ assertion */
> +#define MMC_PM_SKIP_RESUME_PROBE (1 << 2) /* skip the attempt to reidentify the card in powered resume */
>
> #endif
> --
> 1.5.3.6
>
> - Chris.
> --
> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
> One Laptop Per Child
>
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