linux-kernel - [PATCH v2 3/5] fpga manager: xilinx-spi: rework write

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Date:   Thu, 27 Aug 2020 16:32:47 +0200
From:   Luca Ceresoli <luca@...aceresoli.net>
To:     linux-fpga@...r.kernel.org
Cc:     Luca Ceresoli <luca@...aceresoli.net>,
        Moritz Fischer <mdf@...nel.org>, Tom Rix <trix@...hat.com>,
        Michal Simek <michal.simek@...inx.com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Anatolij Gustschin <agust@...x.de>
Subject: [PATCH v2 3/5] fpga manager: xilinx-spi: rework write_complete loop implementation

In preparation to add error checking for gpiod_get_value(), rework
the loop to avoid the duplication of these lines:

	if (gpiod_get_value(conf->done))
		return xilinx_spi_apply_cclk_cycles(conf);

There is little advantage in this rework with current code. However
error checking will expand these two lines to five, making code
duplication more annoying.

Signed-off-by: Luca Ceresoli <luca@...aceresoli.net>

---

This patch is new in v2
---
 drivers/fpga/xilinx-spi.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index 01f494172379..cfc933d70f52 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -151,22 +151,19 @@ static int xilinx_spi_write_complete(struct fpga_manager *mgr,
 				     struct fpga_image_info *info)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
-	unsigned long timeout;
+	unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
 	int ret;
 
-	if (gpiod_get_value(conf->done))
-		return xilinx_spi_apply_cclk_cycles(conf);
-
-	timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+	while (true) {
+		if (gpiod_get_value(conf->done))
+			return xilinx_spi_apply_cclk_cycles(conf);
 
-	while (time_before(jiffies, timeout)) {
+		if (time_after(jiffies, timeout))
+			break;
 
 		ret = xilinx_spi_apply_cclk_cycles(conf);
 		if (ret)
 			return ret;
-
-		if (gpiod_get_value(conf->done))
-			return xilinx_spi_apply_cclk_cycles(conf);
 	}
 
 	dev_err(&mgr->dev, "Timeout after config data transfer\n");
-- 
2.28.0