The patch titled
atmel_serial dma: Misc fixes and cleanups
has been added to the -mm tree. Its filename is
atmel_serial-add-dma-support-fix.patch
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------------------------------------------------------
Subject: atmel_serial dma: Misc fixes and cleanups
From: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Fix some issues identified by Andrew Morton:
* Kill unused PDC_RX_BUF() and PDC_RX_SWITCH() macros
* Simplify TX circ buffer management a bit.
* Don't open-code min()
* Add comment explaining why "count = head - tail" will not cause
wraparound problems.
Also, s/SERIAL_XMIT_SIZE/UART_XMIT_SIZE/ since the latter is what the
serial core circ macros use.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Cc: Remy Bohmer <linux@xxxxxxxxxx>
Cc: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Cc: Andrew Victor <linux@xxxxxxxxxxxx>
Cc: Marc Pignat <marc.pignat@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/serial/atmel_serial.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff -puN drivers/serial/atmel_serial.c~atmel_serial-add-dma-support-fix drivers/serial/atmel_serial.c
--- a/drivers/serial/atmel_serial.c~atmel_serial-add-dma-support-fix
+++ a/drivers/serial/atmel_serial.c
@@ -114,7 +114,7 @@ static void (*atmel_close_hook)(struct u
struct atmel_dma_buffer {
unsigned char *buf;
dma_addr_t dma_addr;
- size_t dma_size;
+ unsigned int dma_size;
unsigned int ofs;
};
@@ -150,9 +150,6 @@ struct atmel_uart_port {
static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
-#define PDC_RX_BUF(port) &(port)->pdc_rx[(port)->pdc_rx_idx]
-#define PDC_RX_SWITCH(port) (port)->pdc_rx_idx = !(port)->pdc_rx_idx
-
#ifdef SUPPORT_SYSRQ
static struct console atmel_console;
#endif
@@ -561,8 +558,7 @@ static void atmel_tx_dma(struct uart_por
int count;
xmit->tail += pdc->ofs;
- if (xmit->tail >= SERIAL_XMIT_SIZE)
- xmit->tail -= SERIAL_XMIT_SIZE;
+ xmit->tail &= UART_XMIT_SIZE - 1;
port->icount.tx += pdc->ofs;
pdc->ofs = 0;
@@ -577,10 +573,7 @@ static void atmel_tx_dma(struct uart_por
pdc->dma_size,
DMA_TO_DEVICE);
- if (xmit->tail < xmit->head)
- count = xmit->head - xmit->tail;
- else
- count = SERIAL_XMIT_SIZE - xmit->tail;
+ count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
pdc->ofs = count;
UART_PUT_TPR(port, pdc->dma_addr + xmit->tail);
@@ -695,14 +688,20 @@ static void atmel_rx_from_dma(struct uar
* ENDRX bit as well, so that we can safely re-enable
* all interrupts below.
*/
- if (head >= pdc->dma_size)
- head = pdc->dma_size;
+ head = min(head, pdc->dma_size);
if (likely(head != tail)) {
dma_sync_single_for_cpu(port->dev, pdc->dma_addr,
pdc->dma_size, DMA_FROM_DEVICE);
+ /*
+ * head will only wrap around when we recycle
+ * the DMA buffer, and when that happens, we
+ * explicitly set tail to 0. So head will
+ * always be greater than tail.
+ */
count = head - tail;
+
tty_insert_flip_string(tty, pdc->buf + pdc->ofs, count);
dma_sync_single_for_device(port->dev, pdc->dma_addr,
@@ -852,9 +851,9 @@ static int atmel_startup(struct uart_por
pdc->buf = xmit->buf;
pdc->dma_addr = dma_map_single(port->dev,
pdc->buf,
- SERIAL_XMIT_SIZE,
+ UART_XMIT_SIZE,
DMA_TO_DEVICE);
- pdc->dma_size = SERIAL_XMIT_SIZE;
+ pdc->dma_size = UART_XMIT_SIZE;
pdc->ofs = 0;
}
_
Patches currently in -mm which might be from hskinnemoen@xxxxxxxxx are
git-avr32.patch
fix-timerfd-breakage-on-avr32-was-re-fix-variable-use-in-avr32-pte_alloc_one.patch
git-mtd.patch
gpiolib-add-drivers-gpio-directory.patch
gpiolib-add-gpio-provider-infrastructure.patch
gpiolib-update-documentation-gpiotxt.patch
gpiolib-pxa-platform-support.patch
gpiolib-pcf857x-i2c-gpio-expander-support.patch
gpiolib-mcp23s08-spi-gpio-expander-support.patch
gpiolib-pca9539-i2c-gpio-expander-support.patch
gpiolib-deprecate-obsolete-pca9539-driver.patch
gpiolib-avr32-at32ap-platform-support.patch
config_highpte-vs-sub-page-page-tables-avr32-fix.patch
read_current_time-cleanups.patch
fix-__const_udelay-declaration-and-definition-mismatches.patch
atmel_spi-throughput-improvement.patch
atmel_spi-chain-dma-transfers.patch
atmel_spi-chain-dma-transfers-update.patch
atmel_spi-fix-dmachain-oops-with-debug-enabled.patch
add-have_oprofile.patch
atmel_lcdfb-validate-display-timings.patch
sanitize-the-type-of-struct-useru_ar0.patch
add-cmpxchg_local-to-avr32.patch
tty-let-architectures-override-the-user-kernel-macros.patch
maintainers-add-haavard-as-maintainer-of-the-atmel_serial-driver.patch
atmel_serial-clean-up-the-code.patch
atmel_serial-use-cpu_relax-when-busy-waiting.patch
atmel_serial-use-existing-console-options-only-if-brg-is-running.patch
atmel_serial-fix-bugs-in-probe-error-path-and-remove.patch
atmel_serial-split-the-interrupt-handler.patch
atmel_serial-add-dma-support.patch
atmel_serial-add-dma-support-fix.patch
atmel_serial-use-container_of-instead-of-direct-cast.patch
atmel_serial-show-tty-name-in-proc-interrupts.patch
basic-pwm-driver-for-avr32-and-at91.patch
basic-pwm-driver-for-avr32-and-at91-fix.patch
pwm-led-driver.patch
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