From 5b00f40f90e7b17c11cf388680f43e8466b3666d Mon Sep 17 00:00:00 2001 From: San Mehat Date: Sat, 21 Nov 2009 09:22:14 -0800 Subject: msm: Add 'execute' datamover callback Based on a patch from Brent DeGraaf: "The datamover supports channels which can be shared amongst devices. As a result, the actual data transfer may occur some time after the request is queued up. Some devices such as mmc host controllers will timeout if a command is issued too far in advance of the actual transfer, so if dma to other devices on the same channel is already in progress or queued up, the added delay can cause pending transfers to fail before they start. This change extends the api to allow a user callback to be invoked just before the actual transfer takes place, thus allowing actions directly associated with the dma transfer, such as device commands, to be invoked with precise timing. Without this mechanism, there is no way for a driver to realize this timing. Also adds a user pointer to the command structure for use by the caller to reference information that may be needed by the callback routine for proper identification and processing associated with that specific request. This change is necessary to fix problems associated with excessive command timeouts and race conditions in the mmc driver." This patch also fixes all the callers of msm_dmov_enqueue_cmd() to ensure their callback function is NULL. Signed-off-by: San Mehat Cc: Brent DeGraaf Cc: Brian Swetland Signed-off-by: Daniel Walker --- arch/arm/mach-msm/dma.c | 5 +++++ arch/arm/mach-msm/include/mach/dma.h | 2 ++ 2 files changed, 7 insertions(+) (limited to 'arch') diff --git a/arch/arm/mach-msm/dma.c b/arch/arm/mach-msm/dma.c index f5420f9585c5..8df798ac70c7 100644 --- a/arch/arm/mach-msm/dma.c +++ b/arch/arm/mach-msm/dma.c @@ -63,6 +63,8 @@ void msm_dmov_enqueue_cmd(unsigned id, struct msm_dmov_cmd *cmd) writel(DMOV_CONFIG_IRQ_EN, DMOV_CONFIG(id)); } #endif + if (cmd->execute_func) + cmd->execute_func(cmd); PRINT_IO("msm_dmov_enqueue_cmd(%d), start command, status %x\n", id, status); list_add_tail(&cmd->list, &active_commands[id]); if (!channel_active) @@ -108,6 +110,7 @@ int msm_dmov_exec_cmd(unsigned id, unsigned int cmdptr) cmd.dmov_cmd.cmdptr = cmdptr; cmd.dmov_cmd.complete_func = dmov_exec_cmdptr_complete_func; + cmd.dmov_cmd.execute_func = NULL; cmd.id = id; init_completion(&cmd.complete); @@ -210,6 +213,8 @@ static irqreturn_t msm_datamover_irq_handler(int irq, void *dev_id) cmd = list_entry(ready_commands[id].next, typeof(*cmd), list); list_del(&cmd->list); list_add_tail(&cmd->list, &active_commands[id]); + if (cmd->execute_func) + cmd->execute_func(cmd); PRINT_FLOW("msm_datamover_irq_handler id %d, start command\n", id); writel(cmd->cmdptr, DMOV_CMD_PTR(id)); } diff --git a/arch/arm/mach-msm/include/mach/dma.h b/arch/arm/mach-msm/include/mach/dma.h index 5ab5bdffab07..78b0ffdf27e8 100644 --- a/arch/arm/mach-msm/include/mach/dma.h +++ b/arch/arm/mach-msm/include/mach/dma.h @@ -28,6 +28,8 @@ struct msm_dmov_cmd { void (*complete_func)(struct msm_dmov_cmd *cmd, unsigned int result, struct msm_dmov_errdata *err); + void (*execute_func)(struct msm_dmov_cmd *cmd); + void *data; }; void msm_dmov_enqueue_cmd(unsigned id, struct msm_dmov_cmd *cmd); -- cgit v1.2.3