serial: Do not treat the IIR register as a bitfield

Message ID	20170329184431.6226-1-oliver@schinagl.nl
State	Not Applicable
Headers	show Return-Path: <linux-tegra-owner@vger.kernel.org> From: Olliver Schinagl <oliver@schinagl.nl> To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Jiri Slaby <jslaby@suse.com>, Laxman Dewangan <ldewangan@nvidia.com>, Stephen Warren <swarren@wwwdotorg.org>, Thierry Reding <thierry.reding@gmail.com>, Alexandre Courbot <gnurou@gmail.com>, "David S . Miller" <davem@davemloft.net> Cc: dev@linux-sunxi.org, Ed Blake <ed.blake@imgtec.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Alexander Sverdlin <alexander.sverdlin@nokia.com>, Yegor Yefremov <yegorslists@googlemail.com>, Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>, Kefeng Wang <wangkefeng.wang@huawei.com>, Heikki Krogerus <heikki.krogerus@linux.intel.com>, Heiko Stuebner <heiko@sntech.de>, Jason Uy <jason.uy@broadcom.com>, Douglas Anderson <dianders@chromium.org>, Peter Hurley <peter@hurleysoftware.com>, Tony Lindgren <tony@atomide.com>, Vignesh R <vigneshr@ti.com>, Thor Thayer <tthayer@opensource.altera.com>, David Lechner <david@lechnology.com>, Jan Kiszka <jan.kiszka@siemens.com>, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, sparclinux@vger.kernel.org, Olliver Schinagl <oliver@schinagl.nl> Subject: [PATCH] serial: Do not treat the IIR register as a bitfield Date: Wed, 29 Mar 2017 20:44:31 +0200 Message-Id: <20170329184431.6226-1-oliver@schinagl.nl> Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 76e03a7de9cc..11b4e3fb0c1d 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -288,6 +288,7 @@ static void serial8250_backup_timeout(unsigned long data) } iir = serial_in(up, UART_IIR); + iir &= UART_IIR_MASK; /* * This should be a safe test for anyone who doesn't trust the @@ -297,14 +298,15 @@ static void serial8250_backup_timeout(unsigned long data) */ lsr = serial_in(up, UART_LSR); up->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; - if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) && + if ((iir == UART_IIR_NO_INT) && + (up->ier & UART_IER_THRI) && (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) && (lsr & UART_LSR_THRE)) { - iir &= ~(UART_IIR_ID | UART_IIR_NO_INT); + iir &= ~(UART_IIR_MASK); iir |= UART_IIR_THRI; } - if (!(iir & UART_IIR_NO_INT)) + if (iir != UART_IIR_NO_INT) serial8250_tx_chars(up); if (up->port.irq) diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index 56aded887771..90cf0e6b4c5b 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -218,7 +218,8 @@ static int dw8250_handle_irq(struct uart_port *p) * This problem has only been observed so far when not in DMA mode * so we limit the workaround only to non-DMA mode. */ - if (!up->dma && ((iir & 0x3f) == UART_IIR_RX_TIMEOUT)) { + iir &= UART_IIR_MASK; + if (!up->dma && (iir == UART_IIR_RX_TIMEOUT)) { spin_lock_irqsave(&p->lock, flags); status = p->serial_in(p, UART_LSR); @@ -231,7 +232,7 @@ static int dw8250_handle_irq(struct uart_port *p) if (serial8250_handle_irq(p, iir)) return 1; - if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { + if (iir == UART_IIR_BUSY) { /* Clear the USR */ (void)p->serial_in(p, d->usr_reg); diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c index 910bfee5a88b..b866343bb485 100644 --- a/drivers/tty/serial/8250/8250_fsl.c +++ b/drivers/tty/serial/8250/8250_fsl.c @@ -33,7 +33,8 @@ int fsl8250_handle_irq(struct uart_port *port) spin_lock_irqsave(&up->port.lock, flags); iir = port->serial_in(port, UART_IIR); - if (iir & UART_IIR_NO_INT) { + iir &= UART_IIR_MASK; + if (iir == UART_IIR_NO_INT) { spin_unlock_irqrestore(&up->port.lock, flags); return 0; } diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index e7e64913a748..ab7c2327d410 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -996,7 +996,7 @@ static int omap_8250_tx_dma(struct uart_8250_port *p) static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { - switch (iir & 0x3f) { + switch (iir & (UART_IIR_MASK | UART_IIR_EXT_MASK)) { case UART_IIR_RLSI: case UART_IIR_RX_TIMEOUT: case UART_IIR_RDI: @@ -1021,7 +1021,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port) serial8250_rpm_get(up); iir = serial_port_in(port, UART_IIR); - if (iir & UART_IIR_NO_INT) { + if ((iir & UART_IIR_MASK) == UART_IIR_NO_INT) { serial8250_rpm_put(up); return 0; } diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 6119516ef5fc..8ee3204d63ba 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1806,7 +1806,7 @@ EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { - switch (iir & 0x3f) { + switch (iir & UART_IIR_MASK) { case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); /* fall-through */ @@ -1825,7 +1825,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) unsigned long flags; struct uart_8250_port *up = up_to_u8250p(port); - if (iir & UART_IIR_NO_INT) + if ((iir & UART_IIR_MASK) == UART_IIR_NO_INT) return 0; spin_lock_irqsave(&port->lock, flags); @@ -1896,7 +1896,7 @@ static int serial8250_tx_threshold_handle_irq(struct uart_port *port) unsigned int iir = serial_port_in(port, UART_IIR); /* TX Threshold IRQ triggered so load up FIFO */ - if ((iir & UART_IIR_ID) == UART_IIR_THRI) { + if ((iir & UART_IIR_MASK) == UART_IIR_THRI) { struct uart_8250_port *up = up_to_u8250p(port); spin_lock_irqsave(&port->lock, flags); @@ -2262,7 +2262,8 @@ int serial8250_do_startup(struct uart_port *port) * don't trust the iir, setup a timer to kick the UART * on a regular basis. */ - if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) || + if ((((iir1 & UART_IIR_MASK) != UART_IIR_NO_INT) && + ((iir & UART_IIR_MASK) == UART_IIR_NO_INT)) || up->port.flags & UPF_BUG_THRE) { up->bugs |= UART_BUG_THRE; } @@ -2313,7 +2314,7 @@ int serial8250_do_startup(struct uart_port *port) iir = serial_port_in(port, UART_IIR); serial_port_out(port, UART_IER, 0); - if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) { + if (lsr & UART_LSR_TEMT && ((iir & UART_IIR_MASK) == UART_IIR_NO_INT)) { if (!(up->bugs & UART_BUG_TXEN)) { up->bugs |= UART_BUG_TXEN; pr_debug("ttyS%d - enabling bad tx status workarounds\n", diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 6c6f82ad8d5c..4e7269b8bf1b 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -569,7 +569,6 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id) { struct uart_omap_port *up = dev_id; unsigned int iir, lsr; - unsigned int type; irqreturn_t ret = IRQ_NONE; int max_count = 256; @@ -578,16 +577,15 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id) do { iir = serial_in(up, UART_IIR); - if (iir & UART_IIR_NO_INT) + iir &= (UART_IIR_MASK | UART_IIR_EXT_MASK); + if (iir == UART_IIR_NO_INT) break; ret = IRQ_HANDLED; lsr = serial_in(up, UART_LSR); /* extract IRQ type from IIR register */ - type = iir & 0x3e; - - switch (type) { + switch (iir) { case UART_IIR_MSI: check_modem_status(up); break; @@ -607,10 +605,12 @@ static irqreturn_t serial_omap_irq(int irq, void *dev_id) break; case UART_IIR_XOFF: /* FALLTHROUGH */ + case UART_IIR_BUSY: + /* FALLTHROUGH */ default: break; } - } while (!(iir & UART_IIR_NO_INT) && max_count--); + } while ((iir != UART_IIR_NO_INT) && max_count--); spin_unlock(&up->port.lock); diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c index 905631df1f8b..37cb17a11b34 100644 --- a/drivers/tty/serial/pxa.c +++ b/drivers/tty/serial/pxa.c @@ -253,7 +253,7 @@ static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id) unsigned int iir, lsr; iir = serial_in(up, UART_IIR); - if (iir & UART_IIR_NO_INT) + if ((iir & UART_IIR_MASK) == UART_IIR_NO_INT) return IRQ_NONE; spin_lock(&up->port.lock); lsr = serial_in(up, UART_LSR); diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c index d92a150c8733..4a084161d1d2 100644 --- a/drivers/tty/serial/serial-tegra.c +++ b/drivers/tty/serial/serial-tegra.c @@ -691,7 +691,8 @@ static irqreturn_t tegra_uart_isr(int irq, void *data) spin_lock_irqsave(&u->lock, flags); while (1) { iir = tegra_uart_read(tup, UART_IIR); - if (iir & UART_IIR_NO_INT) { + iir &= UART_IIR_MASK; + if (iir == UART_IIR_NO_INT) { if (is_rx_int) { tegra_uart_handle_rx_dma(tup); if (tup->rx_in_progress) { diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c index 72df2e1b88af..74e195d4d17e 100644 --- a/drivers/tty/serial/sunsu.c +++ b/drivers/tty/serial/sunsu.c @@ -475,7 +475,7 @@ static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id) spin_lock_irqsave(&up->port.lock, flags); - } while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)); + } while ((serial_in(up, UART_IIR) & UART_IIR_MASK) != UART_IIR_NO_INT); spin_unlock_irqrestore(&up->port.lock, flags); diff --git a/drivers/tty/serial/vr41xx_siu.c b/drivers/tty/serial/vr41xx_siu.c index 439057e8107a..fc3b9bd920e9 100644 --- a/drivers/tty/serial/vr41xx_siu.c +++ b/drivers/tty/serial/vr41xx_siu.c @@ -429,7 +429,7 @@ static irqreturn_t siu_interrupt(int irq, void *dev_id) port = (struct uart_port *)dev_id; iir = siu_read(port, UART_IIR); - if (iir & UART_IIR_NO_INT) + if ((iir & UART_IIR_MASK) == UART_IIR_NO_INT) return IRQ_NONE; lsr = siu_read(port, UART_LSR); diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h index 5db76880b4ad..489522389a10 100644 --- a/include/uapi/linux/serial_reg.h +++ b/include/uapi/linux/serial_reg.h @@ -31,18 +31,18 @@ #define UART_IERX_SLEEP 0x10 /* Enable sleep mode */ #define UART_IIR 2 /* In: Interrupt ID Register */ -#define UART_IIR_NO_INT 0x01 /* No interrupts pending */ -#define UART_IIR_ID 0x0e /* Mask for the interrupt ID */ #define UART_IIR_MSI 0x00 /* Modem status interrupt */ +#define UART_IIR_NO_INT 0x01 /* No interrupts pending */ #define UART_IIR_THRI 0x02 /* Transmitter holding register empty */ #define UART_IIR_RDI 0x04 /* Receiver data interrupt */ #define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */ - #define UART_IIR_BUSY 0x07 /* DesignWare APB Busy Detect */ +#define UART_IIR_RX_TIMEOUT 0x0c /* DesignWare RX Timeout interrupt */ +#define UART_IIR_MASK 0x0f /* DesignWare IIR mask */ -#define UART_IIR_RX_TIMEOUT 0x0c /* OMAP RX Timeout interrupt */ #define UART_IIR_XOFF 0x10 /* OMAP XOFF/Special Character */ #define UART_IIR_CTS_RTS_DSR 0x20 /* OMAP CTS/RTS/DSR Change */ +#define UART_IIR_EXT_MASK 0x30 /* OMAP extended IIR mask */ #define UART_FCR 2 /* Out: FIFO Control Register */ #define UART_FCR_ENABLE_FIFO 0x01 /* Enable the FIFO */

serial: Do not treat the IIR register as a bitfield

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