Re: [PATCH 02/13] EDAC, altera: kill off ACCESS_ONCE()

From: Mark Rutland
Date: Tue Oct 10 2017 - 05:32:00 EST


On Mon, Oct 09, 2017 at 06:12:10PM -0500, Thor Thayer wrote:
> On 10/09/2017 01:28 PM, Mark Rutland wrote:
> >diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
> >index 346c498..11d6419 100644
> >--- a/drivers/edac/altera_edac.c
> >+++ b/drivers/edac/altera_edac.c
> >@@ -175,11 +175,11 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
> > /*
> > * To trigger the error, we need to read the data back
> > * (the data was written with errors above).
> >- * The ACCESS_ONCE macros and printk are used to prevent the
> >+ * The READ_ONCE macros and printk are used to prevent the
> > * the compiler optimizing these reads out.
> > */
> >- reg = ACCESS_ONCE(ptemp[0]);
> >- read_reg = ACCESS_ONCE(ptemp[1]);
> >+ reg = READ_ONCE(ptemp[0]);
> >+ read_reg = READ_ONCE(ptemp[1]);
> > /* Force Read */
> > rmb();
> >@@ -618,7 +618,7 @@ static ssize_t altr_edac_device_trig(struct file *file,
> > for (i = 0; i < (priv->trig_alloc_sz / sizeof(*ptemp)); i++) {
> > /* Read data so we're in the correct state */
> > rmb();
> >- if (ACCESS_ONCE(ptemp[i]))
> >+ if (READ_ONCE(ptemp[i]))
> > result = -1;
> > /* Toggle Error bit (it is latched), leave ECC enabled */
> > writel(error_mask, (drvdata->base + priv->set_err_ofst));
> >@@ -635,7 +635,7 @@ static ssize_t altr_edac_device_trig(struct file *file,
> > /* Read out written data. ECC error caused here */
> > for (i = 0; i < ALTR_TRIGGER_READ_WRD_CNT; i++)
> >- if (ACCESS_ONCE(ptemp[i]) != i)
> >+ if (READ_ONCE(ptemp[i]) != i)
> > edac_printk(KERN_ERR, EDAC_DEVICE,
> > "Read doesn't match written data\n");
> >
>
> Tested on Cyclone5 and Arria10. Thanks!
> Acked-by: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>

Thanks, that's much appreciated!

Mark.