From: Andre Przywara <andre.przywara@arm.com> To: linux@arm.linux.org.uk, gregkh@linuxfoundation.org, jslaby@suse.cz Cc: linux-arm-kernel@lists.infradead.org, rob.herring@linaro.org, arnd@arndb.de, linux-serial@vger.kernel.org, Dave.Martin@arm.com Subject: [PATCH v2 06/10] drivers: PL011: replace UART_MIS reading with _RIS & _IMSC Date: Wed, 4 Mar 2015 17:59:50 +0000 [thread overview] Message-ID: <1425491994-23913-7-git-send-email-andre.przywara@arm.com> (raw) In-Reply-To: <1425491994-23913-1-git-send-email-andre.przywara@arm.com> The PL011 register UART_MIS is actually a bitwise AND of the UART_RIS and the UART_MISC register. Since the SBSA UART does not include the _MIS register, use the two separate registers to get the same behaviour. Since we are inside the spinlock and we read the _IMSC register only once, there should be no race issue. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- drivers/tty/serial/amba-pl011.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 4fe0a0a..b8f46f3 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1418,11 +1418,13 @@ static irqreturn_t pl011_int(int irq, void *dev_id) struct uart_amba_port *uap = dev_id; unsigned long flags; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; + u16 imsc; int handled = 0; unsigned int dummy_read; spin_lock_irqsave(&uap->port.lock, flags); - status = readw(uap->port.membase + UART011_MIS); + imsc = readw(uap->port.membase + UART011_IMSC); + status = readw(uap->port.membase + UART011_RIS) & imsc; if (status) { do { if (uap->vendor->cts_event_workaround) { @@ -1459,7 +1461,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id) if (pass_counter-- == 0) break; - status = readw(uap->port.membase + UART011_MIS); + status = readw(uap->port.membase + UART011_RIS) & imsc; } while (status != 0); handled = 1; } -- 1.7.9.5
WARNING: multiple messages have this Message-ID (diff)
From: andre.przywara@arm.com (Andre Przywara) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 06/10] drivers: PL011: replace UART_MIS reading with _RIS & _IMSC Date: Wed, 4 Mar 2015 17:59:50 +0000 [thread overview] Message-ID: <1425491994-23913-7-git-send-email-andre.przywara@arm.com> (raw) In-Reply-To: <1425491994-23913-1-git-send-email-andre.przywara@arm.com> The PL011 register UART_MIS is actually a bitwise AND of the UART_RIS and the UART_MISC register. Since the SBSA UART does not include the _MIS register, use the two separate registers to get the same behaviour. Since we are inside the spinlock and we read the _IMSC register only once, there should be no race issue. Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- drivers/tty/serial/amba-pl011.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 4fe0a0a..b8f46f3 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1418,11 +1418,13 @@ static irqreturn_t pl011_int(int irq, void *dev_id) struct uart_amba_port *uap = dev_id; unsigned long flags; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; + u16 imsc; int handled = 0; unsigned int dummy_read; spin_lock_irqsave(&uap->port.lock, flags); - status = readw(uap->port.membase + UART011_MIS); + imsc = readw(uap->port.membase + UART011_IMSC); + status = readw(uap->port.membase + UART011_RIS) & imsc; if (status) { do { if (uap->vendor->cts_event_workaround) { @@ -1459,7 +1461,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id) if (pass_counter-- == 0) break; - status = readw(uap->port.membase + UART011_MIS); + status = readw(uap->port.membase + UART011_RIS) & imsc; } while (status != 0); handled = 1; } -- 1.7.9.5
next prev parent reply other threads:[~2015-03-04 17:59 UTC|newest] Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-03-04 17:59 [PATCH v2 00/10] drivers: PL011: add ARM SBSA Generic UART support Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 01/10] drivers: PL011: avoid potential unregister_driver call Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-12 10:42 ` Russell King - ARM Linux 2015-03-12 10:42 ` Russell King - ARM Linux 2015-04-08 15:39 ` Andre Przywara 2015-04-08 15:39 ` Andre Przywara 2015-04-08 18:14 ` Russell King - ARM Linux 2015-04-08 18:14 ` Russell King - ARM Linux 2015-03-04 17:59 ` [PATCH v2 02/10] drivers: PL011: refactor pl011_startup() Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 03/10] drivers: PL011: refactor pl011_shutdown() Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 04/10] drivers: PL011: refactor pl011_set_termios() Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 05/10] drivers: PL011: refactor pl011_probe() Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` Andre Przywara [this message] 2015-03-04 17:59 ` [PATCH v2 06/10] drivers: PL011: replace UART_MIS reading with _RIS & _IMSC Andre Przywara 2015-03-12 10:46 ` Russell King - ARM Linux 2015-03-12 10:46 ` Russell King - ARM Linux 2015-03-04 17:59 ` [PATCH v2 07/10] drivers: PL011: move cts_event workaround into separate function Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-07 3:00 ` Greg KH 2015-03-07 3:00 ` Greg KH 2015-03-04 17:59 ` [PATCH v2 08/10] drivers: PL011: allow avoiding UART enabling/disabling Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 09/10] drivers: PL011: allow to supply fixed option string Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-04 17:59 ` [PATCH v2 10/10] drivers: PL011: add support for the ARM SBSA generic UART Andre Przywara 2015-03-04 17:59 ` Andre Przywara 2015-03-09 15:59 ` Dave Martin 2015-03-09 15:59 ` Dave Martin 2015-03-12 10:52 ` Russell King - ARM Linux 2015-03-12 10:52 ` Russell King - ARM Linux 2015-03-12 13:43 ` Andre Przywara 2015-03-12 13:43 ` Andre Przywara 2015-03-12 13:49 ` Russell King - ARM Linux 2015-03-12 13:49 ` Russell King - ARM Linux 2015-03-12 13:58 ` Andre Przywara 2015-03-12 13:58 ` Andre Przywara 2015-03-07 3:01 ` [PATCH v2 00/10] drivers: PL011: add ARM SBSA Generic UART support Greg KH 2015-03-07 3:01 ` Greg KH
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