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spi: coldfire-qspi: Fix bits per word setting when t->bits_per_word is not set

PATCH In review Axel Lin 3 participants 4 messages Feb 27, 2014 – Mar 2, 2014 1 message not in the archive SPI

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Axel Lin

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#0 lore raw

PATCH 1/1 spi: coldfire-qspi: Fix bits per word setting when t->bits_per_word is not set

This ensures to use spi_device's bits_per_word setting when t->bits_per_word is not set. This looks like a bug introduced by commit 24778be20f8 "spi: convert drivers to use bits_per_word_mask".

Signed-off-by Axel Lin <[email protected]>
---
 drivers/spi/spi-coldfire-qspi.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
drivers/spi/spi-coldfire-qspi.c +6 -2
index c29bbb0..8c85bea 100644
@@ -315,12 +315,16 @@ static int mcfqspi_transfer_one(struct spi_master *master,
 {
 	struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
 	u16 qmr = MCFQSPI_QMR_MSTR;
+	u8 bpw;
 
-	qmr |= t->bits_per_word << 10;
+	bpw = t->bits_per_word ? : spi->bits_per_word;
+
+	qmr |= bpw << 10;
 	if (spi->mode & SPI_CPHA)
 		qmr |= MCFQSPI_QMR_CPHA;
 	if (spi->mode & SPI_CPOL)
 		qmr |= MCFQSPI_QMR_CPOL;
+
 	if (t->speed_hz)
 		qmr |= mcfqspi_qmr_baud(t->speed_hz);
 	else

@@ -328,7 +332,7 @@ static int mcfqspi_transfer_one(struct spi_master *master,
 	mcfqspi_wr_qmr(mcfqspi, qmr);
 
 	mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
-	if (t->bits_per_word == 8)
+	if (bpw == 8)
 		mcfqspi_transfer_msg8(mcfqspi, t->len, t->tx_buf, t->rx_buf);
 	else
 		mcfqspi_transfer_msg16(mcfqspi, t->len / 2, t->tx_buf,
Signature · 8 lines
1.8.1.2



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#1 lore raw
Quoted 3 lines · Axel Lin

This ensures to use spi_device's bits_per_word setting when t->bits_per_word is not set. This looks like a bug introduced by commit 24778be20f8 "spi: convert drivers to use bits_per_word_mask".

I thought the SPI core already contained this kind of logic, so that drivers could rely on t->bits_per_word always being set up? Yes, this:

Quoted 1 line

static int __spi_validate(struct spi_device *spi, struct spi_message *message)

...

Quoted 10 lines
        /**
         * Set transfer bits_per_word and max speed as spi device default if
         * it is not set for this transfer.
         * Set transfer tx_nbits and rx_nbits as single transfer default
         * (SPI_NBITS_SINGLE) if it is not set for this transfer.
         */
        list_for_each_entry(xfer, &message->transfers, transfer_list) {
                message->frame_length += xfer->len;
                if (!xfer->bits_per_word)
                        xfer->bits_per_word = spi->bits_per_word;

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#3 lore raw
In reply to a message not in the archive
Quoted 7 lines · Stephen Warren
Quoted 3 lines · Axel Lin

This ensures to use spi_device's bits_per_word setting when t->bits_per_word is not set. This looks like a bug introduced by commit 24778be20f8 "spi: convert drivers to use bits_per_word_mask".

I thought the SPI core already contained this kind of logic, so that drivers could rely on t->bits_per_word always being set up? Yes, this:

Indeed - if there weren't such logic the better fix would be to add it.

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#4 lore raw
In reply to a message not in the archive

2014-02-28 1:09 GMT+08:00 Stephen Warren <[email protected]>:

Quoted 7 lines · Axel Lin
Quoted 3 lines

This ensures to use spi_device's bits_per_word setting when t->bits_per_word is not set. This looks like a bug introduced by commit 24778be20f8 "spi: convert drivers to use bits_per_word_mask".

I thought the SPI core already contained this kind of logic, so that drivers could rely on t->bits_per_word always being set up? Yes, this:

Hi Stephen,
Yes, you are right and thanks for the review.

Regards,
Axel
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