diff options
author | Sang-Hun Lee <sanlee@nvidia.com> | 2012-06-20 16:16:57 -0700 |
---|---|---|
committer | Simone Willett <swillett@nvidia.com> | 2012-07-01 08:15:10 -0700 |
commit | 4b24801682d7fe5968eedb191c800001c9bd25e4 (patch) | |
tree | 13df96a248b6f8b9cfcf565bd3b99047f5b5c774 /arch/arm/mach-tegra/tegra3_emc.c | |
parent | ba54fa36141c98dd7f1a4ce845f89633715e62a5 (diff) |
ARM: tegra: emc: add reference counting to early ack disablement
Bug 995950
Signed-off-by: Sang-Hun Lee <sanlee@nvidia.com>
Reviewed-on: http://git-master/r/110190
(cherry picked from commit cbfc31fb126cd651157125d1785135eced6587dd)
Change-Id: I44eb889235db82b0efda238b87be5612425afb9d
Reviewed-on: http://git-master/r/110978
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>
Diffstat (limited to 'arch/arm/mach-tegra/tegra3_emc.c')
-rw-r--r-- | arch/arm/mach-tegra/tegra3_emc.c | 39 |
1 files changed, 33 insertions, 6 deletions
diff --git a/arch/arm/mach-tegra/tegra3_emc.c b/arch/arm/mach-tegra/tegra3_emc.c index a70f6aca8c3f..6d430b0a99e3 100644 --- a/arch/arm/mach-tegra/tegra3_emc.c +++ b/arch/arm/mach-tegra/tegra3_emc.c @@ -1,7 +1,7 @@ /* * arch/arm/mach-tegra/tegra3_emc.c * - * Copyright (C) 2011 NVIDIA Corporation + * Copyright (C) 2012 NVIDIA Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -1172,24 +1172,51 @@ int tegra_emc_set_over_temp_state(unsigned long state) return 0; } -int tegra_emc_set_eack_state(unsigned long state) +/* non-zero state value will reduce eack_disable_refcnt */ +static int tegra_emc_set_eack_state(unsigned long state) { unsigned long flags; u32 mc_override; + static int eack_disable_refcnt = 0; spin_lock_irqsave(&emc_access_lock, flags); - mc_override = mc_readl(MC_EMEM_ARB_OVERRIDE); - - if (state) + /* + * refcnt > 0 implies there is at least one client requiring eack + * disabled. refcnt of 0 implies eack is enabled + */ + if (eack_disable_refcnt == 1 && state) { + mc_override = mc_readl(MC_EMEM_ARB_OVERRIDE); enable_early_ack(mc_override); - else + } else if (eack_disable_refcnt == 0 && !state) { + mc_override = mc_readl(MC_EMEM_ARB_OVERRIDE); disable_early_ack(mc_override); + } + + if (state) { + if (likely(eack_disable_refcnt > 0)) { + --eack_disable_refcnt; + } else { + pr_err("%s: Ignored a request to underflow eack " + "disable reference counter\n",__func__); + dump_stack(); + } + } else { + ++eack_disable_refcnt; + } spin_unlock_irqrestore(&emc_access_lock, flags); return 0; } +int tegra_emc_enable_eack(void) { + return tegra_emc_set_eack_state(1); +} + +int tegra_emc_disable_eack(void) { + return tegra_emc_set_eack_state(0); +} + #ifdef CONFIG_DEBUG_FS static struct dentry *emc_debugfs_root; |