Merge branch 'tip/perf/jump-label-2' of git://git.kernel.org/pub/scm/linux/kernel...

[pandora-kernel.git] / arch / arm / plat-omap / dma.c

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index ec7eddf..f5c5b8d 100644 (file)
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -30,6 +30,7 @@
 #include <linux/irq.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/delay.h>
 
 #include <asm/system.h>
 #include <mach/hardware.h>
@@ -996,11 +997,17 @@ void omap_start_dma(int lch)
        l = dma_read(CCR(lch));
 
        /*
-        * Errata: On ES2.0 BUFFERING disable must be set.
-        * This will always fail on ES1.0
+        * Errata: Inter Frame DMA buffering issue (All OMAP2420 and
+        * OMAP2430ES1.0): DMA will wrongly buffer elements if packing and
+        * bursting is enabled. This might result in data gets stalled in
+        * FIFO at the end of the block.
+        * Workaround: DMA channels must have BUFFERING_DISABLED bit set to
+        * guarantee no data will stay in the DMA FIFO in case inter frame
+        * buffering occurs.
         */
-       if (cpu_is_omap24xx())
-               l |= OMAP_DMA_CCR_EN;
+       if (cpu_is_omap2420() ||
+           (cpu_is_omap2430() && (omap_type() == OMAP2430_REV_ES1_0)))
+               l |= OMAP_DMA_CCR_BUFFERING_DISABLE;
 
        l |= OMAP_DMA_CCR_EN;
        dma_write(l, CCR(lch));
@@ -1018,8 +1025,39 @@ void omap_stop_dma(int lch)
                dma_write(0, CICR(lch));
 
        l = dma_read(CCR(lch));
-       l &= ~OMAP_DMA_CCR_EN;
-       dma_write(l, CCR(lch));
+       /* OMAP3 Errata i541: sDMA FIFO draining does not finish */
+       if (cpu_is_omap34xx() && (l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) {
+               int i = 0;
+               u32 sys_cf;
+
+               /* Configure No-Standby */
+               l = dma_read(OCP_SYSCONFIG);
+               sys_cf = l;
+               l &= ~DMA_SYSCONFIG_MIDLEMODE_MASK;
+               l |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
+               dma_write(l , OCP_SYSCONFIG);
+
+               l = dma_read(CCR(lch));
+               l &= ~OMAP_DMA_CCR_EN;
+               dma_write(l, CCR(lch));
+
+               /* Wait for sDMA FIFO drain */
+               l = dma_read(CCR(lch));
+               while (i < 100 && (l & (OMAP_DMA_CCR_RD_ACTIVE |
+                                       OMAP_DMA_CCR_WR_ACTIVE))) {
+                       udelay(5);
+                       i++;
+                       l = dma_read(CCR(lch));
+               }
+               if (i >= 100)
+                       printk(KERN_ERR "DMA drain did not complete on "
+                                       "lch %d\n", lch);
+               /* Restore OCP_SYSCONFIG */
+               dma_write(sys_cf, OCP_SYSCONFIG);
+       } else {
+               l &= ~OMAP_DMA_CCR_EN;
+               dma_write(l, CCR(lch));
+       }
 
        if (!omap_dma_in_1510_mode() && dma_chan[lch].next_lch != -1) {
                int next_lch, cur_lch = lch;