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ARM: OMAP3: Use manual idle for UARTs because of DMA errata
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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>
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Tony Lindgren committed Sep 18, 2014
1 parent 6a08b11 commit a2fc366
Showing 1 changed file with 4 additions and 4 deletions.
8 changes: 4 additions & 4 deletions arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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,
Expand All @@ -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,
Expand Down Expand Up @@ -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,
Expand Down

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