From 94d89efb2c347a82a08a61dbac8565b1087c3259 Mon Sep 17 00:00:00 2001
From: Jorg Schummer <ext-jorg.2.schummer@nokia.com>
Date: Tue, 31 Mar 2009 17:51:21 +0300
Subject: [PATCH] mmc: mmc_rescan detects card change in one run
With this patch, mmc_rescan can detect the removal of an mmc card and
the insertion of (possibly another) card in the same run. This means
that a card change can be detected without having to call
mmc_detect_change multiple times.
This change generalises the core such that it can be easily used by
hosts which provide a mechanism to detect only the presence of a card
reader cover, which has to be taken off in order to insert a card. Other
hosts ("card detect" or "MMC_CAP_NEEDS_POLL") each receive an event when
a card is removed and when a card is inserted, so it is sufficient for
them if mmc_rescan handles only one event at a time. "Cover detect"
hosts, however, only receive events about the cover status. This means
that between 2 subsequent events, both a card removal and a card
insertion can occur. In this case, the pre-patch version of mmc_rescan
would only detect the removal of the previous card but not the insertion
of the new card.
Signed-off-by: Jorg Schummer <ext-jorg.2.schummer@nokia.com>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
---
drivers/mmc/core/core.c | 99 +++++++++++++++++++++++------------------
1 file changed, 55 insertions(+), 44 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 264911732756..23fb2c39d9ed 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -855,61 +855,72 @@ void mmc_rescan(struct work_struct *work)
mmc_bus_get(host);
- if (host->bus_ops == NULL) {
- /*
- * Only we can add a new handler, so it's safe to
- * release the lock here.
- */
+ /* if there is a card registered, check whether it is still present */
+ if ((host->bus_ops != NULL) && host->bus_ops->detect && !host->bus_dead)
+ host->bus_ops->detect(host);
+
+ mmc_bus_put(host);
+
+
+ mmc_bus_get(host);
+
+ /* if there still is a card present, stop here */
+ if (host->bus_ops != NULL) {
mmc_bus_put(host);
+ goto out;
+ }
- if (host->ops->get_cd && host->ops->get_cd(host) == 0)
- goto out;
+ /* detect a newly inserted card */
- mmc_claim_host(host);
+ /*
+ * Only we can add a new handler, so it's safe to
+ * release the lock here.
+ */
+ mmc_bus_put(host);
- mmc_power_up(host);
- mmc_go_idle(host);
+ if (host->ops->get_cd && host->ops->get_cd(host) == 0)
+ goto out;
- mmc_send_if_cond(host, host->ocr_avail);
+ mmc_claim_host(host);
- /*
- * First we search for SDIO...
- */
- err = mmc_send_io_op_cond(host, 0, &ocr);
- if (!err) {
- if (mmc_attach_sdio(host, ocr))
- mmc_power_off(host);
- goto out;
- }
+ mmc_power_up(host);
+ mmc_go_idle(host);
- /*
- * ...then normal SD...
- */
- err = mmc_send_app_op_cond(host, 0, &ocr);
- if (!err) {
- if (mmc_attach_sd(host, ocr))
- mmc_power_off(host);
- goto out;
- }
+ mmc_send_if_cond(host, host->ocr_avail);
- /*
- * ...and finally MMC.
- */
- err = mmc_send_op_cond(host, 0, &ocr);
- if (!err) {
- if (mmc_attach_mmc(host, ocr))
- mmc_power_off(host);
- goto out;
- }
+ /*
+ * First we search for SDIO...
+ */
+ err = mmc_send_io_op_cond(host, 0, &ocr);
+ if (!err) {
+ if (mmc_attach_sdio(host, ocr))
+ mmc_power_off(host);
+ goto out;
+ }
- mmc_release_host(host);
- mmc_power_off(host);
- } else {
- if (host->bus_ops->detect && !host->bus_dead)
- host->bus_ops->detect(host);
+ /*
+ * ...then normal SD...
+ */
+ err = mmc_send_app_op_cond(host, 0, &ocr);
+ if (!err) {
+ if (mmc_attach_sd(host, ocr))
+ mmc_power_off(host);
+ goto out;
+ }
- mmc_bus_put(host);
+ /*
+ * ...and finally MMC.
+ */
+ err = mmc_send_op_cond(host, 0, &ocr);
+ if (!err) {
+ if (mmc_attach_mmc(host, ocr))
+ mmc_power_off(host);
+ goto out;
}
+
+ mmc_release_host(host);
+ mmc_power_off(host);
+
out:
if (host->caps & MMC_CAP_NEEDS_POLL)
mmc_schedule_delayed_work(&host->detect, HZ);
--
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