[PATCH 02/12] ARM: OMAP3: Use force-idle for UARTs because of DMA errata
From: tony@atomide.com (Tony Lindgren)
Date: 2014-09-16 03:11:56
Also in:
linux-omap
Subsystem:
arm port, omap hwmod data, omap2+ support, the rest · Maintainers:
Russell King, Paul Walmsley, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds
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 force-idle mode instead and also force reconfiguring of the IO chain wake-up events. Otherwise systems using Sebastian's 8250 patches with DMA will never enter deeper idle states because of the errata above. Cc: Paul Walmsley <paul@pwsan.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Tony Lindgren <tony@atomide.com> --- arch/arm/mach-omap2/omap_hwmod_3xxx_data.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
index 61cd49d..55f088c 100644
--- a/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_3xxx_data.c@@ -490,7 +490,9 @@ 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_NO_OCP_AUTOIDLE | HWMOD_SWSUP_SIDLE | + HWMOD_FORCE_MSTANDBY | HWMOD_RECONFIG_IO_CHAIN, .prcm = { .omap2 = { .module_offs = CORE_MOD,
@@ -509,7 +511,9 @@ 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_NO_OCP_AUTOIDLE | HWMOD_SWSUP_SIDLE | + HWMOD_FORCE_MSTANDBY | HWMOD_RECONFIG_IO_CHAIN, .prcm = { .omap2 = { .module_offs = CORE_MOD,
@@ -529,7 +533,8 @@ 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_NO_OCP_AUTOIDLE | HWMOD_SWSUP_SIDLE | + HWMOD_FORCE_MSTANDBY | HWMOD_RECONFIG_IO_CHAIN, .prcm = { .omap2 = { .module_offs = OMAP3430_PER_MOD,
@@ -559,7 +564,9 @@ 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_NO_OCP_AUTOIDLE | HWMOD_SWSUP_SIDLE | + HWMOD_FORCE_MSTANDBY | HWMOD_RECONFIG_IO_CHAIN, .prcm = { .omap2 = { .module_offs = OMAP3430_PER_MOD,
--
2.1.0