[patch 2/3] s3cmci - call pio_tasklet from IRQ
From: Christer Weinigel
Date: Mon Sep 08 2008 - 08:59:45 EST
Scheduling a tasklet to perform the pio transfer introduces a bit of
extra processing, just call pio_tasklet directly from the interrupt
instead. Writing up to 64 bytes to a FIFO is probably uses less CPU
than scheduling a tasklet anyway.
Signed-off-by: Christer Weinigel <christer@xxxxxxxxxxx>
Index: linux-2.6.26.2/drivers/mmc/host/s3cmci.c
===================================================================
--- linux-2.6.26.2.orig/drivers/mmc/host/s3cmci.c
+++ linux-2.6.26.2/drivers/mmc/host/s3cmci.c
@@ -361,11 +361,8 @@ static void do_pio_write(struct s3cmci_h
enable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
}
-static void pio_tasklet(unsigned long data)
+static void pio_tasklet(struct s3cmci_host *host)
{
- struct s3cmci_host *host = (struct s3cmci_host *) data;
-
-
disable_irq(host->irq);
if (host->pio_active == XFER_WRITE)
@@ -460,10 +457,10 @@ static irqreturn_t s3cmci_irq(int irq, v
if (!host->dodma) {
if ((host->pio_active == XFER_WRITE) &&
(mci_fsta & S3C2410_SDIFSTA_TFDET)) {
-
disable_imask(host, S3C2410_SDIIMSK_TXFIFOHALF);
- tasklet_schedule(&host->pio_tasklet);
+ pio_tasklet(host);
host->status = "pio tx";
+ goto irq_out;
}
if ((host->pio_active == XFER_READ) &&
@@ -473,8 +470,9 @@ static irqreturn_t s3cmci_irq(int irq, v
S3C2410_SDIIMSK_RXFIFOHALF |
S3C2410_SDIIMSK_RXFIFOLAST);
- tasklet_schedule(&host->pio_tasklet);
+ pio_tasklet(host);
host->status = "pio rx";
+ goto irq_out;
}
}
@@ -595,7 +593,7 @@ close_transfer:
host->complete_what = COMPLETION_FINALIZE;
clear_imask(host);
- tasklet_schedule(&host->pio_tasklet);
+ pio_tasklet(host);
goto irq_out;
@@ -666,7 +664,7 @@ void s3cmci_dma_done_callback(struct s3c
host->complete_what = COMPLETION_FINALIZE;
out:
- tasklet_schedule(&host->pio_tasklet);
+ pio_tasklet(host);
spin_unlock_irqrestore(&host->complete_lock, iflags);
return;
@@ -1198,7 +1196,6 @@ static int __devinit s3cmci_probe(struct
}
spin_lock_init(&host->complete_lock);
- tasklet_init(&host->pio_tasklet, pio_tasklet, (unsigned long) host);
if (is2440) {
host->sdiimsk = S3C2440_SDIIMSK;
@@ -1381,7 +1378,6 @@ static int __devexit s3cmci_remove(struc
clk_put(host->clk);
- tasklet_disable(&host->pio_tasklet);
s3c2410_dma_free(S3CMCI_DMA, &s3cmci_dma_client);
free_irq(host->irq, host);
Index: linux-2.6.26.2/drivers/mmc/host/s3cmci.h
===================================================================
--- linux-2.6.26.2.orig/drivers/mmc/host/s3cmci.h
+++ linux-2.6.26.2/drivers/mmc/host/s3cmci.h
@@ -66,5 +66,4 @@ struct s3cmci_host {
char *status;
unsigned int ccnt, dcnt;
- struct tasklet_struct pio_tasklet;
};
--
"Just how much can I get away with and still go to heaven?"
Christer Weinigel <christer@xxxxxxxxxxx> http://www.weinigel.se
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/