Re: [PATCH v2] mmc: dw_mmc: insmod followed by rmmod will hung for eMMC

Jaehoon Chung
2015-06-01T03:45:21Z

Hi, Prabu.

Thanks for resending the patch.
Will apply this patch at my tree.

Thanks!

Best Regards,
Jaehoon Chung

On 05/28/2015 09:21 PM, Prabu Thangamuthu wrote:
> Remove module of dw_mmc driver will hung for eMMC devices if we follow the
> steps which are listed below,
> insmod dw_mmc.ko
> insmod dw_mmc-pci.ko
> rmmod dw_mmc-pci.ko
>
> The root cause for this issue is, dw_mci_remove() will disable all the
> interrupts by programming 0x0 to INTMASK register then it will call
> dw_mci_cleanup_slot(). But dw_mci_cleanup_slot() is issuing CMD6 to
> disable the eMMC boot partition and it is waiting for Command Complete
> interrupt. Since INTMASK was already cleared by dw_mci_remove(), Command
> Complete interrupt is not reaching the system. This leads to process hung.
>
> Signed-off-by: Prabu Thangamuthu <prabu.t@synopsys.com>
> ---
> Change log v2:
> -Added prefix "mmc:" to the commit message header.
> -Updated the Commit Message.
>
> drivers/mmc/host/dw_mmc.c | 6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 55179f1..40e9d8e 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -2926,15 +2926,15 @@ void dw_mci_remove(struct dw_mci *host)
> {
> int i;
>
> - mci_writel(host, RINTSTS, 0xFFFFFFFF);
> - mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
> -
> for (i = 0; i < host->num_slots; i++) {
> dev_dbg(host->dev, "remove slot %d\n", i);
> if (host->slot[i])
> dw_mci_cleanup_slot(host->slot[i], i);
> }
>
> + mci_writel(host, RINTSTS, 0xFFFFFFFF);
> + mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */
> +
> /* disable clock to CIU */
> mci_writel(host, CLKENA, 0);
> mci_writel(host, CLKSRC, 0);
>