[U-Boot] [PATCH] mmc/dwmmc: remove recursive FIFO threshold setup

[Alexey Brodkin]

Removed code works properly only once after power-up because on every
"first" invocation of "dwmci_init" existing value of "fifo_size" is used
for calculation of itself. More over other bits in the same register
(namely TX watermark and burst size) get corrupted (lost forever till
the next power-toggle).

I understand that usually (in production systems) U-Boot starts only
once and then passes control to Linux kernel etc. But when you do
U-Boot debugging it might be loaded in memory via JTAG multiple times.

Also I wasn't able to find any instance of "host->fifoth_val" usage so I
believe it's safe to just remove this code completely.

Another important thing - in the latest Linux kernel driver for DW MMC
comtroller I don't see any utilization (configuration/modificatoin) of
the register in question (SDMMC_FIFOTH). That's why I think we may want
to keep it untouched as well so we don't force a situation when kernel
driver gets DW MMC unexpectedly configured by U-Boot.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>

Cc: Mischa Jonker <mjonker at synopsys.com>
Cc: Alim Akhtar <alim.akhtar at samsung.com>
Cc: Rajeshwari Shinde <rajeshwari.s at samsung.com>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
Cc: Amar <amarendra.xt at samsung.com>
Cc: Kyungmin Park <kyungmin.park at samsung.com>
Cc: Hatim Ali <hatim.rv at samsung.com>
Cc: Minkyu Kang <mk7.kang at samsung.com>
Cc: Simon Glass <sjg at chromium.org>
Cc: Pantelis Antoniou <panto at antoniou-consulting.com>
Cc: Andy Fleming <afleming at freescale.com>
---
 drivers/mmc/dw_mmc.c | 9 ---------
 include/dwmmc.h      | 1 -
 2 files changed, 10 deletions(-)

diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c
index 1e0f72b..166124d 100644
--- a/drivers/mmc/dw_mmc.c
+++ b/drivers/mmc/dw_mmc.c
@@ -300,7 +300,6 @@ static void dwmci_set_ios(struct mmc *mmc)
 static int dwmci_init(struct mmc *mmc)
 {
 	struct dwmci_host *host = (struct dwmci_host *)mmc->priv;
-	u32 fifo_size;
 
 	if (host->quirks & DWMCI_QUIRK_DISABLE_SMU) {
 		dwmci_writel(host, EMMCP_MPSBEGIN0, 0);
@@ -330,14 +329,6 @@ static int dwmci_init(struct mmc *mmc)
 	dwmci_writel(host, DWMCI_IDINTEN, 0);
 	dwmci_writel(host, DWMCI_BMOD, 1);
 
-	if (!host->fifoth_val) {
-		fifo_size = dwmci_readl(host, DWMCI_FIFOTH);
-		fifo_size = ((fifo_size & RX_WMARK_MASK) >> RX_WMARK_SHIFT) + 1;
-		host->fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size / 2 - 1) |
-			TX_WMARK(fifo_size / 2);
-	}
-	dwmci_writel(host, DWMCI_FIFOTH, host->fifoth_val);
-
 	dwmci_writel(host, DWMCI_CLKENA, 0);
 	dwmci_writel(host, DWMCI_CLKSRC, 0);
 
diff --git a/include/dwmmc.h b/include/dwmmc.h
index 6c91143..20cd1eb 100644
--- a/include/dwmmc.h
+++ b/include/dwmmc.h
@@ -137,7 +137,6 @@ struct dwmci_host {
 	int dev_index;
 	int buswidth;
 	u32 clksel_val;
-	u32 fifoth_val;
 	struct mmc *mmc;
 
 	void (*clksel)(struct dwmci_host *host);
-- 
1.8.4.2