At the start of each request, re-tune if needed and
then hold off re-tuning again until the request is done.
Note that though there is one function that starts
requests (mmc_start_request) there are two that wait for
the request to be done (mmc_wait_for_req_done and
mmc_wait_for_data_req_done). Also note that
mmc_wait_for_data_req_done can return even when the
request is not done (which allows the block driver
to prepare a newly arrived request while still
waiting for the previous request).
This patch ensures re-tuning is held for the duration
of a request. Subsequent patches will also hold
re-tuning at other times when it might cause a
conflict.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/core.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index e9ab5ff..6dad56d 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -192,9 +192,21 @@ static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
unsigned int i, sz;
struct scatterlist *sg;
#endif
+ int err;
+
+ mmc_retune_hold(host);
+
if (mmc_card_removed(host->card))
return -ENOMEDIUM;
+ err = mmc_retune_recheck(host);
+ if (err) {
+ /* Retry path expects the clock to be held */
+ if (mrq->cmd->retries)
+ mmc_host_clk_hold(host);
+ return err;
+ }
+
if (mrq->sbc) {
pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
mmc_hostname(host), mrq->sbc->opcode,
@@ -427,12 +439,11 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host,
}
} else if (context_info->is_new_req) {
context_info->is_new_req = false;
- if (!next_req) {
- err = MMC_BLK_NEW_REQUEST;
- break; /* return err */
- }
+ if (!next_req)
+ return MMC_BLK_NEW_REQUEST;
}
}
+ mmc_retune_release(host);
return err;
}
@@ -473,6 +484,8 @@ static void mmc_wait_for_req_done(struct mmc_host *host,
cmd->error = 0;
host->ops->request(host, mrq);
}
+
+ mmc_retune_release(host);
}
/**
--
1.9.1
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