[PATCH 3/3] mmc: mmci: Reverse IRQ handling for the arm_variant

[Ulf Hansson]

On 16 June 2014 09:58, Ulf Hansson <ulf.hansson at linaro.org> wrote:
> Commit "mmc: mmci: Handle CMD irq before DATA irq", caused an issue
> when using the ARM model of the PL181 and running QEMU.
>
> The bug was reported for the following QEMU version:
> $ qemu-system-arm -version
> QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.1), Copyright
> (c) 2003-2008 Fabrice Bellard
>
> To resolve the problem, let's restore the old behavior were the DATA
> irq is handled prior the CMD irq, but only for the arm_variant, which
> the problem was reported for.
>
> Reported-by: John Stultz <john.stultz at linaro.org>
> Cc: Peter Maydell <peter.maydell at linaro.org>
> Cc: Russell King <linux at arm.linux.org.uk>
> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
> ---
>  drivers/mmc/host/mmci.c |   11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index 5d20bfba..c7e1d42 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -74,6 +74,7 @@ static unsigned int fmax = 515633;
>   * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
>   * @explicit_mclk_control: enable explicit mclk control in driver.
>   * @qcom_fifo: enables qcom specific fifo pio read logic.
> + * @reversed_irq_handling: handle data irq before cmd irq.
>   */
>  struct variant_data {
>         unsigned int            clkreg;
> @@ -97,6 +98,7 @@ struct variant_data {
>         bool                    pwrreg_nopower;
>         bool                    explicit_mclk_control;
>         bool                    qcom_fifo;
> +       bool                    reversed_irq_handling;
>  };

I noticed that I should enable reversed_irq_handling for the
arm_variant as well.

Will send a v2 in a moment.

Kind regards
Ulf Hansson

>
>  static struct variant_data variant_arm = {
> @@ -1236,8 +1238,13 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
>
>                 dev_dbg(mmc_dev(host->mmc), "irq0 (data+cmd) %08x\n", status);
>
> -               mmci_cmd_irq(host, host->cmd, status);
> -               mmci_data_irq(host, host->data, status);
> +               if (host->variant->reversed_irq_handling) {
> +                       mmci_data_irq(host, host->data, status);
> +                       mmci_cmd_irq(host, host->cmd, status);
> +               } else {
> +                       mmci_cmd_irq(host, host->cmd, status);
> +                       mmci_data_irq(host, host->data, status);
> +               }
>
>                 /* Don't poll for busy completion in irq context. */
>                 if (host->busy_status)
> --
> 1.7.9.5
>