Re: [PATCH 1/1] dw_mmc: insmod followed by rmmod will hung for eMMC

From: Ulf Hansson
Date: Fri May 22 2015 - 09:21:33 EST


On 18 May 2015 at 16:23, Prabu Thangamuthu <Prabu.T@xxxxxxxxxxxx> wrote:
> Removing dw_mmc driver immediately after inserting the dw_mmc driver is

I guess it hangs even if you remove it after a couple of days? :-)

Perhaps makes this a bit more clear?

> getting hung for eMMC device. Root cause for this issue is, dw_mci_remove
> will disable all the interrupts then it will call dw_mci_cleanup_slot.
> dw_mci_cleanup_slot is issuing CMD6 to disable boot partition access and
> it's 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.

/s dw_mci_remove / dw_mci_remove()

>
> Signed-off-by: Prabu Thangamuthu <prabu.t@xxxxxxxxxxxx>

This patch looks good overall, but please send a new version with
updated changelog. Moreover, please use "mmc: dw_mmc:" as prefix for
the commit message header.

Kind regards
Uffe

> ---
> 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 5f5adaf..f0a0aff 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -2941,15 +2941,15 @@ 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);
> --
> 1.7.6.5
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