commit: 91ab252ac5a5c3461dd6910797611e9172626aed
From: Guennadi Liakhovetski <[email protected]>
Date: Wed, 22 Aug 2012 06:49:47 +0000
Subject: mmc: sh-mmcif: avoid oops on spurious interrupts (second try)

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 <[email protected]>
Signed-off-by: Guennadi Liakhovetski <[email protected]>
Tested-by: Tetsuyuki Kobayashi <[email protected]>
Cc: [email protected]
Signed-off-by: Chris Ball <[email protected]>
---
 drivers/mmc/host/sh_mmcif.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index 43cd0b5..7eaee3e 100644
--- 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;
-- 
1.7.3.4
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