ARM: OMAP3: Use manual idle for UARTs because of DMA errata
authorTony Lindgren <tony@atomide.com>
Thu, 18 Sep 2014 15:58:49 +0000 (08:58 -0700)
committerTony Lindgren <tony@atomide.com>
Thu, 18 Sep 2014 15:58:49 +0000 (08:58 -0700)
In sprz318f.pdf "Usage Note 2.7" says that UARTs cannot acknowledge
idle requests in smartidle mode when configured for DMA operations.
This prevents L4 from going idle. So let's use manual idle mode
instead.

Otherwise systems using Sebastian's 8250 patches with DMA will
never enter deeper idle states because of the errata above.

Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
arch/arm/mach-omap2/omap_hwmod_3xxx_data.c

index 61cd49d..2a78b09 100644 (file)
@@ -490,7 +490,7 @@ static struct omap_hwmod omap3xxx_uart1_hwmod = {
        .mpu_irqs       = omap2_uart1_mpu_irqs,
        .sdma_reqs      = omap2_uart1_sdma_reqs,
        .main_clk       = "uart1_fck",
-       .flags          = DEBUG_TI81XXUART1_FLAGS | HWMOD_SWSUP_SIDLE_ACT,
+       .flags          = DEBUG_TI81XXUART1_FLAGS | HWMOD_SWSUP_SIDLE,
        .prcm           = {
                .omap2 = {
                        .module_offs = CORE_MOD,
@@ -509,7 +509,7 @@ static struct omap_hwmod omap3xxx_uart2_hwmod = {
        .mpu_irqs       = omap2_uart2_mpu_irqs,
        .sdma_reqs      = omap2_uart2_sdma_reqs,
        .main_clk       = "uart2_fck",
-       .flags          = DEBUG_TI81XXUART2_FLAGS | HWMOD_SWSUP_SIDLE_ACT,
+       .flags          = DEBUG_TI81XXUART2_FLAGS | HWMOD_SWSUP_SIDLE,
        .prcm           = {
                .omap2 = {
                        .module_offs = CORE_MOD,
@@ -529,7 +529,7 @@ static struct omap_hwmod omap3xxx_uart3_hwmod = {
        .sdma_reqs      = omap2_uart3_sdma_reqs,
        .main_clk       = "uart3_fck",
        .flags          = DEBUG_OMAP3UART3_FLAGS | DEBUG_TI81XXUART3_FLAGS |
-                               HWMOD_SWSUP_SIDLE_ACT,
+                               HWMOD_SWSUP_SIDLE,
        .prcm           = {
                .omap2 = {
                        .module_offs = OMAP3430_PER_MOD,
@@ -559,7 +559,7 @@ static struct omap_hwmod omap36xx_uart4_hwmod = {
        .mpu_irqs       = uart4_mpu_irqs,
        .sdma_reqs      = uart4_sdma_reqs,
        .main_clk       = "uart4_fck",
-       .flags          = DEBUG_OMAP3UART4_FLAGS | HWMOD_SWSUP_SIDLE_ACT,
+       .flags          = DEBUG_OMAP3UART4_FLAGS | HWMOD_SWSUP_SIDLE,
        .prcm           = {
                .omap2 = {
                        .module_offs = OMAP3430_PER_MOD,