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From: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
	grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org,
	dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
	alan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org
Cc: alek.du-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org
Subject: [PATCH v2 2/4] spi/dw_spi: remove the un-necessary flush()
Date: Wed, 30 Mar 2011 23:09:53 +0800	[thread overview]
Message-ID: <1301497795-6924-3-git-send-email-feng.tang@intel.com> (raw)
In-Reply-To: <1301497795-6924-1-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

From: Alek Du <alek.du-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

The flush() is used to drain all the left data in rx fifo, currently
is is always called together with disabling hw. But from spec, disabling
hw will also reset all the fifo, so flush() is not needed.

Signed-off-by: Alek Du <alek.du-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Feng Tang <feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/spi/dw_spi.c |   15 +--------------
 1 files changed, 1 insertions(+), 14 deletions(-)

diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index c4fca3d..d3aaf8d 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -173,17 +173,6 @@ static void wait_till_not_busy(struct dw_spi *dws)
 		"DW SPI: Status keeps busy for 5000us after a read/write!\n");
 }
 
-static void flush(struct dw_spi *dws)
-{
-	while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) {
-		dw_readw(dws, dr);
-		cpu_relax();
-	}
-
-	wait_till_not_busy(dws);
-}
-
-
 static int dw_writer(struct dw_spi *dws)
 {
 	u16 txw = 0;
@@ -297,8 +286,7 @@ static void giveback(struct dw_spi *dws)
 
 static void int_error_stop(struct dw_spi *dws, const char *msg)
 {
-	/* Stop and reset hw */
-	flush(dws);
+	/* Stop the hw */
 	spi_enable_chip(dws, 0);
 
 	dev_err(&dws->master->dev, "%s\n", msg);
@@ -800,7 +788,6 @@ static void spi_hw_init(struct dw_spi *dws)
 	spi_enable_chip(dws, 0);
 	spi_mask_intr(dws, 0xff);
 	spi_enable_chip(dws, 1);
-	flush(dws);
 
 	/*
 	 * Try to detect the FIFO depth if not set by interface driver,
-- 
1.7.0.4


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  parent reply	other threads:[~2011-03-30 15:09 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-30 15:09 [PATCH v2 0/4] patch serie for dw_spi driver Feng Tang
     [not found] ` <1301497795-6924-1-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2011-03-30 15:09   ` [PATCH v2 1/4] spi/dw_spi: unify the low level read/write routines Feng Tang
     [not found]     ` <1301497795-6924-2-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2011-03-31  3:32       ` Grant Likely
2011-03-30 15:09   ` Feng Tang [this message]
     [not found]     ` <1301497795-6924-3-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2011-03-31  3:32       ` [PATCH v2 2/4] spi/dw_spi: remove the un-necessary flush() Grant Likely
2011-03-30 15:09   ` [PATCH v2 3/4] spi/dw_spi: change poll mode transfer from byte ops to batch ops Feng Tang
     [not found]     ` <1301497795-6924-4-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2011-03-31  3:32       ` Grant Likely
2011-03-31  9:54       ` Alan Cox
     [not found]         ` <20110331105448.0f6d0bd4-Z/y2cZnRghHXmaaqVzeoHQ@public.gmane.org>
2011-03-31 12:54           ` Du, Alek
2011-03-31 13:13           ` Grant Likely
2011-04-25  7:46             ` Feng Tang
2011-04-25  8:54               ` Du, Alek
2011-03-30 15:09   ` [PATCH v2 4/4] spi/dw_spi: improve the interrupt mode with the " Feng Tang
     [not found]     ` <1301497795-6924-5-git-send-email-feng.tang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2011-03-31  3:32       ` Grant Likely

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