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Revert "serial: 8250_dma: don't bother DMA with small transfers"

PATCH In review Frederic Danis 3 participants 3 messages Oct 9, 2015 – Oct 13, 2015

Subsystems (2)
Bluetooth drivers TTY layer and serial drivers
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Frederic Danis

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#0 lore raw

PATCH v3 1/1 Revert "serial: 8250_dma: don't bother DMA with small transfers"

This reverts commit 9119fba0cfeda6d415c9f068df66838a104b87cb.

This commit prevents from sending "big" file using Bluetooth. When sending a lot of data quickly through the Bluetooth interface, and after a variable amount of data sent, transfer fails with error:

    kernel: [  415.247453] Bluetooth: hci0 hardware error 0x00

Found on T100TA.

After reverting this commit, send works fine for any file size.

Signed-off-by Frederic Danis <[email protected]>
Fixes 9119fba0cfed (serial: 8250_dma: don't bother DMA with small

transfers)
Cc: [email protected]
---
v3: Add Fixes and Cc tags
v2: Re-send to correct people

 drivers/tty/serial/8250/8250_dma.c | 4 ----
 1 file changed, 4 deletions(-)
drivers/tty/serial/8250/8250_dma.c +0 -4
index b503071..78259d3 100644
@@ -77,10 +77,6 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 		return 0;
 
 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
-	if (dma->tx_size < p->port.fifosize) {
-		ret = -EINVAL;
-		goto err;
-	}
 
 	desc = dmaengine_prep_slave_single(dma->txchan,
 					   dma->tx_addr + xmit->tail,
Signature · 1 line
1.9.1
Reviewed-by on v3 1/1
#1 lore raw
Quoted 7 lines · Frederic Danis

This reverts commit 9119fba0cfeda6d415c9f068df66838a104b87cb.

This commit prevents from sending "big" file using Bluetooth. When sending a lot of data quickly through the Bluetooth interface, and after a variable amount of data sent, transfer fails with error:

    kernel: [  415.247453] Bluetooth: hci0 hardware error 0x00
Quoted 8 lines

Found on T100TA.

After reverting this commit, send works fine for any file size.

Signed-off-by Frederic Danis <[email protected]>
Fixes 9119fba0cfed (serial: 8250_dma: don't bother DMA with small

transfers)
Cc: [email protected]

FWIW:

Reviewed-by Heikki Krogerus <[email protected]>
Quoted 24 lines

---
v3: Add Fixes and Cc tags
v2: Re-send to correct people

 drivers/tty/serial/8250/8250_dma.c | 4 ----
 1 file changed, 4 deletions(-)
drivers/tty/serial/8250/8250_dma.c +0 -4
index b503071..78259d3 100644
@@ -77,10 +77,6 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 		return 0;
 
 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
-	if (dma->tx_size < p->port.fifosize) {
-		ret = -EINVAL;
-		goto err;
-	}
 
 	desc = dmaengine_prep_slave_single(dma->txchan,
 					   dma->tx_addr + xmit->tail,
Signature · 1 line
1.9.1
Signature · 1 line
heikki
Acked-by on v3 1/1
#2 lore raw
In reply to Frederic Danis
Quoted 8 lines · Frederic Danis

This reverts commit 9119fba0cfeda6d415c9f068df66838a104b87cb.

This commit prevents from sending "big" file using Bluetooth. When sending a lot of data quickly through the Bluetooth interface, and
after a variable amount of data sent, transfer fails with error:

    kernel: [  415.247453] Bluetooth: hci0 hardware error 0x00
Quoted 8 lines

Found on T100TA.

After reverting this commit, send works fine for any file size.

Signed-off-by Frederic Danis <[email protected]>
Fixes 9119fba0cfed (serial: 8250_dma: don't bother DMA with small

transfers)
Cc: [email protected]

Acked-by Andy Shevchenko <[email protected]>
Quoted 25 lines

---
v3: Add Fixes and Cc tags
v2: Re-send to correct people

 drivers/tty/serial/8250/8250_dma.c | 4 ----
 1 file changed, 4 deletions(-)
drivers/tty/serial/8250/8250_dma.c +0 -4
index b503071..78259d3 100644
@@ -77,10 +77,6 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 		return 0;
 
 	dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, 
 UART_XMIT_SIZE);
-	if (dma->tx_size < p->port.fifosize) {
-		ret = -EINVAL;
-		goto err;
-	}
 
 	desc = dmaengine_prep_slave_single(dma->txchan,

dma->tx_addr + xmit
->tail,

Signature · 2 lines
Andy Shevchenko <[email protected]>
Intel Finland Oy