mmc: sh-mmcif: avoid oops on spurious interrupts (second try)

commit 91ab252ac5a5c3461dd6910797611e9172626aed upstream.

On some systems, e.g., kzm9g, MMCIF interfaces can produce spurious
interrupts without any active request. To prevent the Oops, that results
in such cases, don't dereference the mmc request pointer until we make
sure, that we are indeed processing such a request.

Reported-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index ab10a1de3773d05f6ceaaa6edfe6e4200ecccc3f..2671202833b9946019e36967ddad20d3edf55458 100644 (file)
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -1104,7 +1104,6 @@ static irqreturn_t sh_mmcif_irqt(int irq, void *dev_id)
 {
        struct sh_mmcif_host *host = dev_id;
        struct mmc_request *mrq = host->mrq;
-       struct mmc_data *data = mrq->data;
 
        cancel_delayed_work_sync(&host->timeout_work);
 
@@ -1152,13 +1151,14 @@ static irqreturn_t sh_mmcif_irqt(int irq, void *dev_id)
        case MMCIF_WAIT_FOR_READ_END:
        case MMCIF_WAIT_FOR_WRITE_END:
                if (host->sd_error)
-                       data->error = sh_mmcif_error_manage(host);
+                       mrq->data->error = sh_mmcif_error_manage(host);
                break;
        default:
                BUG();
        }
 
        if (host->wait_for != MMCIF_WAIT_FOR_STOP) {
+               struct mmc_data *data = mrq->data;
                if (!mrq->cmd->error && data && !data->error)
                        data->bytes_xfered =
                                data->blocks * data->blksz;