mmc: msm_sdcc: Reduce command timeouts and improve reliability.

Based on an original patch by Brent DeGraaf:

"Previous versions of the SD driver were beset with excessive command
timeouts. These timeouts were silent by default, but happened
frequently, especially during heavy system activity and concurrent
access of two or more SD devices. Worst case, these timeouts would
occasionally hit at the end of a successful write, resulting in false
failures that could adversely affect journaling file systems if timing
was unfortunate. This update tightens the association and timing between
dma transfers and the commands that trigger them by utilizing a new api
implemented in the datamover.  In addition, it also fixes a dma cache
coherency issue that was exposed during testing of this fix that
occasionally resulted in card corruption.  Processing of results in the
interrupt status routine was modified to process command results prior to
data because overwritten command results were observed during testing
since the data section can result in command issuances of its own.
This change also eliminates the software command timeout, relying entirely
on the hardware version, since the software timeout was found to cause
problems of its own after extensive testing (having hardware timer and
software timers addressing the same issue was found to cause a race
condition under heavy system load)."

This change originally added PROG_DONE handling, which has been split out
into a separate patch. Also on our platform, the data mover driver maintains
coherency to ensure API reliability, so the above mentioned cache corruption
issue was not an issue for us.

Signed-off-by: San Mehat <san@google.com>
Cc: Brian Swetland <swetland@google.com>

Change-Id: Ifbf17cfafb858106d73bf49af52b5161a265a484
Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/mmc/host/msm_sdcc.h b/drivers/mmc/host/msm_sdcc.h
index 6846bd7dff2..361cb6efd24 100644
--- a/drivers/mmc/host/msm_sdcc.h
+++ b/drivers/mmc/host/msm_sdcc.h
@@ -171,6 +171,7 @@ struct msmsdcc_dma_data {
 	int				channel;
 	struct msmsdcc_host		*host;
 	int				busy; /* Set if DM is busy */
+	int				active;
 };
 
 struct msmsdcc_pio_data {
@@ -213,7 +214,6 @@ struct msmsdcc_host {
 	struct clk		*clk;		/* main MMC bus clock */
 	struct clk		*pclk;		/* SDCC peripheral bus clock */
 	unsigned int		clks_on;	/* set if clocks are enabled */
-	struct timer_list	command_timer;
 	struct timer_list	busclk_timer;
 	int			use_bustimer;
 
@@ -235,6 +235,18 @@ struct msmsdcc_host {
 	struct msmsdcc_pio_data	pio;
 	int			cmdpoll;
 	struct msmsdcc_stats	stats;
+
+#ifdef CONFIG_MMC_MSM7X00A_RESUME_IN_WQ
+	struct work_struct	resume_task;
+#endif
+
+	/* Command parameters */
+	unsigned int		cmd_timeout;
+	unsigned int		cmd_pio_irqmask;
+	unsigned int		cmd_datactrl;
+	struct mmc_command	*cmd_cmd;
+	u32			cmd_c;
+
 };
 
 #endif