[RFC} sdhci.c set_ios -- disable global interrupts and Question on Power Management

[Philip Rakity]

Pierre,

I am preparing a patch to just diable to interrupt line to the SD controller so 
global interrupts are not locked out.  This
will allow mdelay to work correctly in the routines the set_ios() calls.

The pm_ calls  remove the lock before being called and restore it afterwards.  
Is this just to ensure interrupts are globally
enabled ?  If so, I can simplify my patch deleting the original spin_lock calls 
that surround the pm_ calls.

Philip


>From 782c474f1abe992a203ad76594db025414332e67 Mon Sep 17 00:00:00 2001
From: Philip Rakity <prak...@marvell.com>
Date: Tue, 25 Jan 2011 16:04:42 -0800
Subject: [PATCH 1/2] sdhci: sdhci.c: Do not disable global interrupts while 
waiting in set_ios

holding the spin_lock with all interrupts disabled
is not good form when doing mdelay.
set_ios calls routines that need to delay for power to
stabalize or for chip issues when quirks are defined.

disable only our interupt and spin_lock on the chip
instead of spin_lock with all interrupts disabled.

Signed-off-by: Philip Rakity <prak...@marvell.com>
Signed-off-by: Mark F. Brown <ma...@marvell.com>
---
 drivers/mmc/host/sdhci.c |   15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 655617c..1a88303 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1161,13 +1161,13 @@ static void sdhci_request(struct mmc_host *mmc, struct 
mmc_request *mrq)
 static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
        struct sdhci_host *host;
-       unsigned long flags;
        unsigned int lastclock;
        u8 ctrl;
 
        host = mmc_priv(mmc);
 
-       spin_lock_irqsave(&host->lock, flags);
+       disable_irq(host->irq);
+       spin_lock(&host->lock);
 
        if (host->flags & SDHCI_DEVICE_DEAD)
                goto out;
@@ -1180,14 +1180,14 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct 
mmc_ios *ios)
        lastclock = host->iosclock;
        host->iosclock = ios->clock;
        if (lastclock == 0 && ios->clock != 0) {
-               spin_unlock_irqrestore(&host->lock, flags);
+               spin_unlock(&host->lock);
                pm_runtime_get_sync(host->mmc->parent);
-               spin_lock_irqsave(&host->lock, flags);
+               spin_lock(&host->lock);
        } else if (lastclock != 0 && ios->clock == 0) {
-               spin_unlock_irqrestore(&host->lock, flags);
+               spin_unlock(&host->lock);
                pm_runtime_mark_last_busy(host->mmc->parent);
                pm_runtime_put_autosuspend(host->mmc->parent);
-               spin_lock_irqsave(&host->lock, flags);
+               spin_lock(&host->lock);
        }
        /* no need to configure the rest.. */
        if (host->iosclock == 0)
@@ -1257,7 +1257,8 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct 
mmc_ios *ios)
 
 out:
        mmiowb();
-       spin_unlock_irqrestore(&host->lock, flags);
+       spin_unlock(&host->lock);
+       enable_irq(host->irq);
 }
 
 static int sdhci_get_ro(struct mmc_host *mmc)
-- 
1.7.0.4


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