On Tue, Feb 26, 2008 at 08:14:20AM -0600, Olof Johansson wrote:
> Hi,
>
> On Tue, Feb 26, 2008 at 10:46:06PM +1100, Michael Ellerman wrote:
> > On Wed, 2008-02-20 at 20:57 -0600, Olof Johansson wrote:
> > > + i = 1000;
> > > + pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, 0);
> > > + while ((i > 0) && (pasemi_read_dma_reg(PAS_DMA_COM_RXSTA) & 1))
> > > + i--;
> > > + if (i < 0)
> > > + printk(KERN_INFO "Warning: Could not disable RX section\n");
> > > +
> > > + i = 1000;
> > > + pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, 0);
> > > + while ((i > 0) && (pasemi_read_dma_reg(PAS_DMA_COM_TXSTA) & 1))
> > > + i--;
> >
> > This kind of caught my eye, is it still going to work when the next core
> > is twice as fast?
>
> Actually, I added the variable right before posting, I used to have an
> infinite loop there while testing the patch. I've never seen it do more
> than a few rounds, so I'm not that worried.
>
> We already have a similar loop in the channel shutdown code, but it runs
> a bit longer. I might bring that over instead. Thanks for pointing it
> out.
FYI; I've commited in this change, rest of the patch is identical.
diff --git a/arch/powerpc/platforms/pasemi/dma_lib.c
b/arch/powerpc/platforms/pasemi/dma_lib.c
index c529d8d..48cb7c9 100644
--- a/arch/powerpc/platforms/pasemi/dma_lib.c
+++ b/arch/powerpc/platforms/pasemi/dma_lib.c
@@ -17,6 +17,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
@@ -410,6 +411,7 @@ int pasemi_dma_init(void)
struct resource res;
struct device_node *dn;
int i, intf, err = 0;
+ unsigned long timeout;
u32 tmp;
if (!machine_is(pasemi))
@@ -478,6 +480,34 @@ int pasemi_dma_init(void)
for (i = 0; i < MAX_RXCH; i++)
__set_bit(i, rxch_free);
+ timeout = jiffies + HZ;
+ pasemi_write_dma_reg(PAS_DMA_COM_RXCMD, 0);
+ while (pasemi_read_dma_reg(PAS_DMA_COM_RXSTA) & 1) {
+ if (time_after(jiffies, timeout)) {
+ pr_warning("Warning: Could not disable RX section\n");
+ break;
+ }
+ }
+
+ timeout = jiffies + HZ;
+ pasemi_write_dma_reg(PAS_DMA_COM_TXCMD, 0);
+ while (pasemi_read_dma_reg(PAS_DMA_COM_TXSTA) & 1) {
+ if (time_after(jiffies, timeout)) {
+ pr_warning("Warning: Could not disable TX section\n");
+ break;
+ }
+ }
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