diff mbox series

[08/21] spi: s3c64xx: move error check up to avoid rechecking

Message ID 20240123153421.715951-9-tudor.ambarus@linaro.org (mailing list archive)
State New, archived
Headers show
Series spi: s3c64xx: winter cleanup and gs101 support | expand

Commit Message

Tudor Ambarus Jan. 23, 2024, 3:34 p.m. UTC
Check the return value of wait_for_completion_timeout() immediately
after the call so that we avoid checking the return value twice.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
 drivers/spi/spi-s3c64xx.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

Comments

André Draszik Jan. 24, 2024, 9:21 a.m. UTC | #1
Hi Tudor,

On Tue, 2024-01-23 at 15:34 +0000, Tudor Ambarus wrote:
> @@ -538,13 +538,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
>  			cpu_relax();
>  			status = readl(regs + S3C64XX_SPI_STATUS);
>  		}
> -
>  	}
>  
> -	/* If timed out while checking rx/tx status return error */
> -	if (!val)
> -		return -EIO;
> -

This change behaviour of this function. The loop just above adjusts val and it is used to
determine if there was a timeout or not:

	if (val && !xfer->rx_buf) {
		val = msecs_to_loops(10);
		status = readl(regs + S3C64XX_SPI_STATUS);
		while ((TX_FIFO_LVL(status, sdd)
			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
		       && --val) {
			cpu_relax();
			status = readl(regs + S3C64XX_SPI_STATUS);
		}


That doesn't work anymore now.

Cheers,
Andre'
Tudor Ambarus Jan. 24, 2024, 9:32 a.m. UTC | #2
On 1/24/24 09:21, André Draszik wrote:
> Hi Tudor,
> 

Hi!

> On Tue, 2024-01-23 at 15:34 +0000, Tudor Ambarus wrote:
>> @@ -538,13 +538,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
>>  			cpu_relax();
>>  			status = readl(regs + S3C64XX_SPI_STATUS);
>>  		}
>> -
>>  	}
>>  
>> -	/* If timed out while checking rx/tx status return error */
>> -	if (!val)
>> -		return -EIO;
>> -
> 
> This change behaviour of this function. The loop just above adjusts val and it is used to
> determine if there was a timeout or not:
> 
> 	if (val && !xfer->rx_buf) {
> 		val = msecs_to_loops(10);
> 		status = readl(regs + S3C64XX_SPI_STATUS);
> 		while ((TX_FIFO_LVL(status, sdd)
> 			|| !S3C64XX_SPI_ST_TX_DONE(status, sdd))
> 		       && --val) {
> 			cpu_relax();
> 			status = readl(regs + S3C64XX_SPI_STATUS);
> 		}
>
Oh, yes, the timeout in this block. You're right, I'll drop the patch.
Thanks!

ta
diff mbox series

Patch

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 16eea56892a2..128c3b8211ce 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -519,17 +519,17 @@  static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 
 	val = msecs_to_jiffies(ms) + 10;
 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
-
+	if (!val)
+		return -EIO;
 	/*
-	 * If the previous xfer was completed within timeout, then
-	 * proceed further else return -EIO.
+	 * If the previous xfer was completed within timeout proceed further.
 	 * DmaTx returns after simply writing data in the FIFO,
 	 * w/o waiting for real transmission on the bus to finish.
 	 * DmaRx returns only after Dma read data from FIFO which
 	 * needs bus transmission to finish, so we don't worry if
 	 * Xfer involved Rx(with or without Tx).
 	 */
-	if (val && !xfer->rx_buf) {
+	if (!xfer->rx_buf) {
 		val = msecs_to_loops(10);
 		status = readl(regs + S3C64XX_SPI_STATUS);
 		while ((TX_FIFO_LVL(status, sdd)
@@ -538,13 +538,8 @@  static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 			cpu_relax();
 			status = readl(regs + S3C64XX_SPI_STATUS);
 		}
-
 	}
 
-	/* If timed out while checking rx/tx status return error */
-	if (!val)
-		return -EIO;
-
 	return 0;
 }