Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753009Ab1CXMhU (ORCPT ); Thu, 24 Mar 2011 08:37:20 -0400 Received: from na3sys009aog106.obsmtp.com ([74.125.149.77]:40463 "EHLO na3sys009aog106.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750803Ab1CXMhQ (ORCPT ); Thu, 24 Mar 2011 08:37:16 -0400 Date: Thu, 24 Mar 2011 14:37:11 +0200 From: Felipe Balbi To: Toby Gray Cc: balbi@ti.com, Alan Cox , Stefan Bigler , Greg KH , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: TTY loosing data with u_serial gadget Message-ID: <20110324123708.GK14602@legolas.emea.dhcp.ti.com> Reply-To: balbi@ti.com References: <4D8121F6.9060600@keymile.com> <20110317000408.GA18911@kroah.com> <4D8389EC.5030704@keymile.com> <20110318170801.GA2857@legolas.emea.dhcp.ti.com> <20110318180657.11570887@lxorguk.ukuu.org.uk> <20110321093255.GE1837@legolas.emea.dhcp.ti.com> <20110322085344.GN1837@legolas.emea.dhcp.ti.com> <4D8B341C.4010406@realvnc.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="KFztAG8eRSV9hGtP" Content-Disposition: inline In-Reply-To: <4D8B341C.4010406@realvnc.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 28955 Lines: 896 --KFztAG8eRSV9hGtP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi, On Thu, Mar 24, 2011 at 12:07:56PM +0000, Toby Gray wrote: > On 22/03/2011 08:53, Felipe Balbi wrote: > >Patch attached, please give it a good round of test as I don't have how > >to exercise all line disciplines. I ran 100 randconfigs over night and > >no warnings or erros on that area, at least not that I could see (so > >many warning while compiling the kernel :-( ) > > Is this patch missing the changes to tty_buffer.c that were in > http://permalink.gmane.org/gmane.linux.usb.general/28976 > > Without the changes to tty_buffer.c to use the value returned from > the receive_buf call then doesn't this patch not work correctly? > > Also with this patch, does the receive_room member of tty_struct have > any use? As far as I can tell it's also referenced in paste_selection > in drivers/tty/vt/selection.c. It's the case that past_selection uses > receive_buf so shouldn't it be updated to use the new return value > semantics for receive_buf? > > Without modifying tty_buffer.c to not make use of receive_room I > can't get console terminals to work with this patch. Although I have > to admit that I've been applying the patch to 2.6.35.3 as that's the > kernel my development board is currently using, but I can't see any > immediate reason why the most recent kernel would be any different. > However I'm still fairly new to the interactions between the various > bits of tty code and drivers, so I could just be missing an important > change that's in 2.6.38+. you are right, thanks for noticing that. Attached is an updated patch. I left removal of receive_room out of this patch to prevent too invasive change, that can be done on a separate patch. -- balbi --KFztAG8eRSV9hGtP Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="0001-tty-make-receive_buf-return-the-amout-of-bytes-receiv.diff" >From 7f6e7b8bc6eed9ee1347d7555540801435a3cc43 Mon Sep 17 00:00:00 2001 From: Felipe Balbi Date: Mon, 21 Mar 2011 12:25:08 +0200 Subject: [PATCH] tty: make receive_buf() return the amout of bytes received Organization: Texas Instruments\n it makes it simpler to keep track of the amount of bytes received and simplifies how flush_to_ldisc counts the remaining bytes. It also fixes a bug of lost bytes on n_tty when flushing too many bytes via the USB serial gadget driver. Signed-off-by: Felipe Balbi --- drivers/bluetooth/hci_ldisc.c | 12 +++++-- drivers/input/serio/serport.c | 10 +++++- drivers/isdn/gigaset/ser-gigaset.c | 8 +++-- drivers/misc/ti-st/st_core.c | 6 ++- drivers/net/caif/caif_serial.c | 6 ++- drivers/net/can/slcan.c | 9 ++++-- drivers/net/hamradio/6pack.c | 8 +++-- drivers/net/hamradio/mkiss.c | 11 ++++-- drivers/net/irda/irtty-sir.c | 16 ++++++---- drivers/net/ppp_async.c | 6 ++- drivers/net/ppp_synctty.c | 6 ++- drivers/net/slip.c | 11 ++++-- drivers/net/wan/x25_asy.c | 7 +++- drivers/tty/n_gsm.c | 6 ++- drivers/tty/n_hdlc.c | 18 ++++++----- drivers/tty/n_r3964.c | 10 ++++-- drivers/tty/n_tty.c | 54 ++++++++--------------------------- drivers/tty/tty_buffer.c | 7 ++-- drivers/tty/vt/selection.c | 3 +- include/linux/tty_ldisc.h | 9 +++-- 20 files changed, 118 insertions(+), 105 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index 3c6cabc..72c542b 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -357,22 +357,26 @@ static void hci_uart_tty_wakeup(struct tty_struct *tty) * * Return Value: None */ -static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *flags, int count) +static unsigned int hci_uart_tty_receive(struct tty_struct *tty, + const u8 *data, char *flags, int count) { struct hci_uart *hu = (void *)tty->disc_data; + int received; if (!hu || tty != hu->tty) - return; + return -ENODEV; if (!test_bit(HCI_UART_PROTO_SET, &hu->flags)) - return; + return -EINVAL; spin_lock(&hu->rx_lock); - hu->proto->recv(hu, (void *) data, count); + received = hu->proto->recv(hu, (void *) data, count); hu->hdev->stat.byte_rx += count; spin_unlock(&hu->rx_lock); tty_unthrottle(tty); + + return received; } static int hci_uart_register_dev(struct hci_uart *hu) diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c index 8755f5f..f369896 100644 --- a/drivers/input/serio/serport.c +++ b/drivers/input/serio/serport.c @@ -120,17 +120,21 @@ static void serport_ldisc_close(struct tty_struct *tty) * 'interrupt' routine. */ -static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) +static unsigned int serport_ldisc_receive(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct serport *serport = (struct serport*) tty->disc_data; unsigned long flags; unsigned int ch_flags; + int ret = 0; int i; spin_lock_irqsave(&serport->lock, flags); - if (!test_bit(SERPORT_ACTIVE, &serport->flags)) + if (!test_bit(SERPORT_ACTIVE, &serport->flags)) { + ret = -EINVAL; goto out; + } for (i = 0; i < count; i++) { switch (fp[i]) { @@ -152,6 +156,8 @@ static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *c out: spin_unlock_irqrestore(&serport->lock, flags); + + return ret == 0 ? count : ret; } /* diff --git a/drivers/isdn/gigaset/ser-gigaset.c b/drivers/isdn/gigaset/ser-gigaset.c index 0ef09d0..14e57b4 100644 --- a/drivers/isdn/gigaset/ser-gigaset.c +++ b/drivers/isdn/gigaset/ser-gigaset.c @@ -674,7 +674,7 @@ gigaset_tty_ioctl(struct tty_struct *tty, struct file *file, * cflags buffer containing error flags for received characters (ignored) * count number of received characters */ -static void +static unsigned int gigaset_tty_receive(struct tty_struct *tty, const unsigned char *buf, char *cflags, int count) { @@ -683,12 +683,12 @@ gigaset_tty_receive(struct tty_struct *tty, const unsigned char *buf, struct inbuf_t *inbuf; if (!cs) - return; + return -ENODEV; inbuf = cs->inbuf; if (!inbuf) { dev_err(cs->dev, "%s: no inbuf\n", __func__); cs_put(cs); - return; + return -EINVAL; } tail = inbuf->tail; @@ -725,6 +725,8 @@ gigaset_tty_receive(struct tty_struct *tty, const unsigned char *buf, gig_dbg(DEBUG_INTR, "%s-->BH", __func__); gigaset_schedule_event(cs); cs_put(cs); + + return count; } /* diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c index f9aad06..5d23d89 100644 --- a/drivers/misc/ti-st/st_core.c +++ b/drivers/misc/ti-st/st_core.c @@ -866,8 +866,8 @@ static void st_tty_close(struct tty_struct *tty) pr_debug("%s: done ", __func__); } -static void st_tty_receive(struct tty_struct *tty, const unsigned char *data, - char *tty_flags, int count) +static unsigned int st_tty_receive(struct tty_struct *tty, + const unsigned char *data, char *tty_flags, int count) { #ifdef VERBOSE @@ -881,6 +881,8 @@ static void st_tty_receive(struct tty_struct *tty, const unsigned char *data, */ st_recv(tty->disc_data, data, count); pr_debug("done %s", __func__); + + return count; } /* wake-up function called in from the TTY layer diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 3df0c0f..73c7e03 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -167,8 +167,8 @@ static inline void debugfs_tx(struct ser_device *ser, const u8 *data, int size) #endif -static void ldisc_receive(struct tty_struct *tty, const u8 *data, - char *flags, int count) +static unsigned int ldisc_receive(struct tty_struct *tty, + const u8 *data, char *flags, int count) { struct sk_buff *skb = NULL; struct ser_device *ser; @@ -215,6 +215,8 @@ static void ldisc_receive(struct tty_struct *tty, const u8 *data, } else ++ser->dev->stats.rx_dropped; update_tty_status(ser); + + return count; } static int handle_tx(struct ser_device *ser) diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c index b423965..c600954 100644 --- a/drivers/net/can/slcan.c +++ b/drivers/net/can/slcan.c @@ -425,16 +425,17 @@ static void slc_setup(struct net_device *dev) * in parallel */ -static void slcan_receive_buf(struct tty_struct *tty, +static unsigned int slcan_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct slcan *sl = (struct slcan *) tty->disc_data; + int bytes = count; if (!sl || sl->magic != SLCAN_MAGIC || !netif_running(sl->dev)) - return; + return -ENODEV; /* Read the characters out of the buffer */ - while (count--) { + while (bytes--) { if (fp && *fp++) { if (!test_and_set_bit(SLF_ERROR, &sl->flags)) sl->dev->stats.rx_errors++; @@ -443,6 +444,8 @@ static void slcan_receive_buf(struct tty_struct *tty, } slcan_unesc(sl, *cp++); } + + return count; } /************************************ diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index 3e5d0b6..9920896 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -456,7 +456,7 @@ out: * a block of 6pack data has been received, which can now be decapsulated * and sent on to some IP layer for further processing. */ -static void sixpack_receive_buf(struct tty_struct *tty, +static unsigned int sixpack_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct sixpack *sp; @@ -464,11 +464,11 @@ static void sixpack_receive_buf(struct tty_struct *tty, int count1; if (!count) - return; + return 0; sp = sp_get(tty); if (!sp) - return; + return -ENODEV; memcpy(buf, cp, count < sizeof(buf) ? count : sizeof(buf)); @@ -487,6 +487,8 @@ static void sixpack_receive_buf(struct tty_struct *tty, sp_put(sp); tty_unthrottle(tty); + + return count1; } /* diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c index 4c62839..0e4f235 100644 --- a/drivers/net/hamradio/mkiss.c +++ b/drivers/net/hamradio/mkiss.c @@ -923,13 +923,14 @@ static long mkiss_compat_ioctl(struct tty_struct *tty, struct file *file, * a block of data has been received, which can now be decapsulated * and sent on to the AX.25 layer for further processing. */ -static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int mkiss_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct mkiss *ax = mkiss_get(tty); + int bytes = count; if (!ax) - return; + return -ENODEV; /* * Argh! mtu change time! - costs us the packet part received @@ -939,7 +940,7 @@ static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp, ax_changedmtu(ax); /* Read the characters out of the buffer */ - while (count--) { + while (bytes--) { if (fp != NULL && *fp++) { if (!test_and_set_bit(AXF_ERROR, &ax->flags)) ax->dev->stats.rx_errors++; @@ -952,6 +953,8 @@ static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp, mkiss_put(ax); tty_unthrottle(tty); + + return count; } /* diff --git a/drivers/net/irda/irtty-sir.c b/drivers/net/irda/irtty-sir.c index ee1dde5..b4e6480 100644 --- a/drivers/net/irda/irtty-sir.c +++ b/drivers/net/irda/irtty-sir.c @@ -216,23 +216,23 @@ static int irtty_do_write(struct sir_dev *dev, const unsigned char *ptr, size_t * usbserial: urb-complete-interrupt / softint */ -static void irtty_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int irtty_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct sir_dev *dev; struct sirtty_cb *priv = tty->disc_data; int i; - IRDA_ASSERT(priv != NULL, return;); - IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return;); + IRDA_ASSERT(priv != NULL, return -ENODEV;); + IRDA_ASSERT(priv->magic == IRTTY_MAGIC, return -EINVAL;); if (unlikely(count==0)) /* yes, this happens */ - return; + return 0; dev = priv->dev; if (!dev) { IRDA_WARNING("%s(), not ready yet!\n", __func__); - return; + return -ENODEV; } for (i = 0; i < count; i++) { @@ -242,11 +242,13 @@ static void irtty_receive_buf(struct tty_struct *tty, const unsigned char *cp, if (fp && *fp++) { IRDA_DEBUG(0, "Framing or parity error!\n"); sirdev_receive(dev, NULL, 0); /* notify sir_dev (updating stats) */ - return; + return -EINVAL; } } sirdev_receive(dev, cp, count); + + return count; } /* diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c index a1b82c9..53872d7 100644 --- a/drivers/net/ppp_async.c +++ b/drivers/net/ppp_async.c @@ -340,7 +340,7 @@ ppp_asynctty_poll(struct tty_struct *tty, struct file *file, poll_table *wait) } /* May sleep, don't call from interrupt level or with interrupts disabled */ -static void +static unsigned int ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf, char *cflags, int count) { @@ -348,7 +348,7 @@ ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf, unsigned long flags; if (!ap) - return; + return -ENODEV; spin_lock_irqsave(&ap->recv_lock, flags); ppp_async_input(ap, buf, cflags, count); spin_unlock_irqrestore(&ap->recv_lock, flags); @@ -356,6 +356,8 @@ ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf, tasklet_schedule(&ap->tsk); ap_put(ap); tty_unthrottle(tty); + + return count; } static void diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c index 4e6b72f..01122cd 100644 --- a/drivers/net/ppp_synctty.c +++ b/drivers/net/ppp_synctty.c @@ -381,7 +381,7 @@ ppp_sync_poll(struct tty_struct *tty, struct file *file, poll_table *wait) } /* May sleep, don't call from interrupt level or with interrupts disabled */ -static void +static unsigned int ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf, char *cflags, int count) { @@ -389,7 +389,7 @@ ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf, unsigned long flags; if (!ap) - return; + return -ENODEV; spin_lock_irqsave(&ap->recv_lock, flags); ppp_sync_input(ap, buf, cflags, count); spin_unlock_irqrestore(&ap->recv_lock, flags); @@ -397,6 +397,8 @@ ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf, tasklet_schedule(&ap->tsk); sp_put(ap); tty_unthrottle(tty); + + return count; } static void diff --git a/drivers/net/slip.c b/drivers/net/slip.c index 86cbb9e..86718d3 100644 --- a/drivers/net/slip.c +++ b/drivers/net/slip.c @@ -670,16 +670,17 @@ static void sl_setup(struct net_device *dev) * in parallel */ -static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int slip_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct slip *sl = tty->disc_data; + int bytes = count; if (!sl || sl->magic != SLIP_MAGIC || !netif_running(sl->dev)) - return; + return -ENODEV; /* Read the characters out of the buffer */ - while (count--) { + while (bytes--) { if (fp && *fp++) { if (!test_and_set_bit(SLF_ERROR, &sl->flags)) sl->dev->stats.rx_errors++; @@ -693,6 +694,8 @@ static void slip_receive_buf(struct tty_struct *tty, const unsigned char *cp, #endif slip_unesc(sl, *cp++); } + + return count; } /************************************ diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c index 24297b2..40398bf 100644 --- a/drivers/net/wan/x25_asy.c +++ b/drivers/net/wan/x25_asy.c @@ -517,17 +517,18 @@ static int x25_asy_close(struct net_device *dev) * and sent on to some IP layer for further processing. */ -static void x25_asy_receive_buf(struct tty_struct *tty, +static unsigned int x25_asy_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { struct x25_asy *sl = tty->disc_data; + int bytes = count; if (!sl || sl->magic != X25_ASY_MAGIC || !netif_running(sl->dev)) return; /* Read the characters out of the buffer */ - while (count--) { + while (bytes--) { if (fp && *fp++) { if (!test_and_set_bit(SLF_ERROR, &sl->flags)) sl->dev->stats.rx_errors++; @@ -536,6 +537,8 @@ static void x25_asy_receive_buf(struct tty_struct *tty, } x25_asy_unesc(sl, *cp++); } + + return count; } /* diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index aa2e5d3..a606331 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -2139,8 +2139,8 @@ static void gsmld_detach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) gsm->tty = NULL; } -static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int gsmld_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct gsm_mux *gsm = tty->disc_data; const unsigned char *dp; @@ -2174,6 +2174,8 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp, } /* FASYNC if needed ? */ /* If clogged call tty_throttle(tty); */ + + return count; } /** diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c index 52fc0c9..517e376 100644 --- a/drivers/tty/n_hdlc.c +++ b/drivers/tty/n_hdlc.c @@ -189,8 +189,8 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp, poll_table *wait); static int n_hdlc_tty_open(struct tty_struct *tty); static void n_hdlc_tty_close(struct tty_struct *tty); -static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *cp, - char *fp, int count); +static unsigned int n_hdlc_tty_receive(struct tty_struct *tty, + const __u8 *cp, char *fp, int count); static void n_hdlc_tty_wakeup(struct tty_struct *tty); #define bset(p,b) ((p)[(b) >> 5] |= (1 << ((b) & 0x1f))) @@ -510,8 +510,8 @@ static void n_hdlc_tty_wakeup(struct tty_struct *tty) * Called by tty low level driver when receive data is available. Data is * interpreted as one HDLC frame. */ -static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data, - char *flags, int count) +static unsigned int n_hdlc_tty_receive(struct tty_struct *tty, + const __u8 *data, char *flags, int count) { register struct n_hdlc *n_hdlc = tty2n_hdlc (tty); register struct n_hdlc_buf *buf; @@ -522,20 +522,20 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data, /* This can happen if stuff comes in on the backup tty */ if (!n_hdlc || tty != n_hdlc->tty) - return; + return -ENODEV; /* verify line is using HDLC discipline */ if (n_hdlc->magic != HDLC_MAGIC) { printk("%s(%d) line not using HDLC discipline\n", __FILE__,__LINE__); - return; + return -EINVAL; } if ( count>maxframe ) { if (debuglevel >= DEBUG_LEVEL_INFO) printk("%s(%d) rx count>maxframesize, data discarded\n", __FILE__,__LINE__); - return; + return -EINVAL; } /* get a free HDLC buffer */ @@ -551,7 +551,7 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data, if (debuglevel >= DEBUG_LEVEL_INFO) printk("%s(%d) no more rx buffers, data discarded\n", __FILE__,__LINE__); - return; + return -EINVAL; } /* copy received data to HDLC buffer */ @@ -566,6 +566,8 @@ static void n_hdlc_tty_receive(struct tty_struct *tty, const __u8 *data, if (n_hdlc->tty->fasync != NULL) kill_fasync (&n_hdlc->tty->fasync, SIGIO, POLL_IN); + return count; + } /* end of n_hdlc_tty_receive() */ /** diff --git a/drivers/tty/n_r3964.c b/drivers/tty/n_r3964.c index 88dda0c..ea725c5 100644 --- a/drivers/tty/n_r3964.c +++ b/drivers/tty/n_r3964.c @@ -140,8 +140,8 @@ static int r3964_ioctl(struct tty_struct *tty, struct file *file, static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old); static unsigned int r3964_poll(struct tty_struct *tty, struct file *file, struct poll_table_struct *wait); -static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count); +static unsigned int r3964_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count); static struct tty_ldisc_ops tty_ldisc_N_R3964 = { .owner = THIS_MODULE, @@ -1240,8 +1240,8 @@ static unsigned int r3964_poll(struct tty_struct *tty, struct file *file, return result; } -static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int r3964_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { struct r3964_info *pInfo = tty->disc_data; const unsigned char *p; @@ -1258,6 +1258,8 @@ static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp, } } + + return count; } MODULE_LICENSE("GPL"); diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 428f4fe..8e0f113 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -81,32 +81,6 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x, return put_user(x, ptr); } -/** - * n_tty_set__room - receive space - * @tty: terminal - * - * Called by the driver to find out how much data it is - * permitted to feed to the line discipline without any being lost - * and thus to manage flow control. Not serialized. Answers for the - * "instant". - */ - -static void n_tty_set_room(struct tty_struct *tty) -{ - /* tty->read_cnt is not read locked ? */ - int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; - - /* - * If we are doing input canonicalization, and there are no - * pending newlines, let characters through without limit, so - * that erase characters will be handled. Other excess - * characters will be beeped. - */ - if (left <= 0) - left = tty->icanon && !tty->canon_data; - tty->receive_room = left; -} - static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) { if (tty->read_cnt < N_TTY_BUF_SIZE) { @@ -178,7 +152,6 @@ static void reset_buffer_flags(struct tty_struct *tty) tty->canon_head = tty->canon_data = tty->erasing = 0; memset(&tty->read_flags, 0, sizeof tty->read_flags); - n_tty_set_room(tty); check_unthrottle(tty); } @@ -1354,17 +1327,19 @@ static void n_tty_write_wakeup(struct tty_struct *tty) * calls one at a time and in order (or using flush_to_ldisc) */ -static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, - char *fp, int count) +static unsigned int n_tty_receive_buf(struct tty_struct *tty, + const unsigned char *cp, char *fp, int count) { const unsigned char *p; char *f, flags = TTY_NORMAL; int i; char buf[64]; unsigned long cpuflags; + int left; + int ret = 0; if (!tty->read_buf) - return; + return 0; if (tty->real_raw) { spin_lock_irqsave(&tty->read_lock, cpuflags); @@ -1374,6 +1349,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, memcpy(tty->read_buf + tty->read_head, cp, i); tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); tty->read_cnt += i; + ret += i; cp += i; count -= i; @@ -1385,6 +1361,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, tty->read_cnt += i; spin_unlock_irqrestore(&tty->read_lock, cpuflags); } else { + ret = count; for (i = count, p = cp, f = fp; i; i--, p++) { if (f) flags = *f++; @@ -1412,8 +1389,6 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, tty->ops->flush_chars(tty); } - n_tty_set_room(tty); - if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) || L_EXTPROC(tty)) { kill_fasync(&tty->fasync, SIGIO, POLL_IN); @@ -1426,8 +1401,12 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, * mode. We don't want to throttle the driver if we're in * canonical mode and don't have a newline yet! */ - if (tty->receive_room < TTY_THRESHOLD_THROTTLE) + left = N_TTY_BUF_SIZE - tty->read_cnt - 1; + + if (left < TTY_THRESHOLD_THROTTLE) tty_throttle(tty); + + return ret; } int is_ignored(int sig) @@ -1471,7 +1450,6 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { tty->raw = 1; tty->real_raw = 1; - n_tty_set_room(tty); return; } if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || @@ -1524,7 +1502,6 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) else tty->real_raw = 0; } - n_tty_set_room(tty); /* The termios change make the tty ready for I/O */ wake_up_interruptible(&tty->write_wait); wake_up_interruptible(&tty->read_wait); @@ -1806,8 +1783,6 @@ do_it_again: retval = -ERESTARTSYS; break; } - /* FIXME: does n_tty_set_room need locking ? */ - n_tty_set_room(tty); timeout = schedule_timeout(timeout); continue; } @@ -1879,10 +1854,8 @@ do_it_again: * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, * we won't get any more characters. */ - if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) { - n_tty_set_room(tty); + if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) check_unthrottle(tty); - } if (b - buf >= minimum) break; @@ -1904,7 +1877,6 @@ do_it_again: } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) goto do_it_again; - n_tty_set_room(tty); return retval; } diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index d8210ca..2f119e2 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -416,6 +416,7 @@ static void flush_to_ldisc(struct work_struct *work) struct tty_buffer *head, *tail = tty->buf.tail; int seen_tail = 0; while ((head = tty->buf.head) != NULL) { + int copied; int count; char *char_buf; unsigned char *flag_buf; @@ -446,15 +447,13 @@ static void flush_to_ldisc(struct work_struct *work) schedule_delayed_work(&tty->buf.work, 1); break; } - if (count > tty->receive_room) - count = tty->receive_room; char_buf = head->char_buf_ptr + head->read; flag_buf = head->flag_buf_ptr + head->read; - head->read += count; spin_unlock_irqrestore(&tty->buf.lock, flags); - disc->ops->receive_buf(tty, char_buf, + copied = disc->ops->receive_buf(tty, char_buf, flag_buf, count); spin_lock_irqsave(&tty->buf.lock, flags); + head->read += copied; } clear_bit(TTY_FLUSHING, &tty->flags); } diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c index c956ed6..c912cb9 100644 --- a/drivers/tty/vt/selection.c +++ b/drivers/tty/vt/selection.c @@ -335,8 +335,7 @@ int paste_selection(struct tty_struct *tty) continue; } count = sel_buffer_lth - pasted; - count = min(count, tty->receive_room); - tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted, + count = tty->ldisc->ops->receive_buf(tty, sel_buffer + pasted, NULL, count); pasted += count; } diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h index ff7dc08..5b07792 100644 --- a/include/linux/tty_ldisc.h +++ b/include/linux/tty_ldisc.h @@ -76,7 +76,7 @@ * tty device. It is solely the responsibility of the line * discipline to handle poll requests. * - * void (*receive_buf)(struct tty_struct *, const unsigned char *cp, + * unsigned int (*receive_buf)(struct tty_struct *, const unsigned char *cp, * char *fp, int count); * * This function is called by the low-level tty driver to send @@ -84,7 +84,8 @@ * processing. is a pointer to the buffer of input * character received by the device. is a pointer to a * pointer of flag bytes which indicate whether a character was - * received with a parity error, etc. + * received with a parity error, etc. Returns the amount of bytes + * received. * * void (*write_wakeup)(struct tty_struct *); * @@ -140,8 +141,8 @@ struct tty_ldisc_ops { /* * The following routines are called from below. */ - void (*receive_buf)(struct tty_struct *, const unsigned char *cp, - char *fp, int count); + unsigned int (*receive_buf)(struct tty_struct *, + const unsigned char *cp, char *fp, int count); void (*write_wakeup)(struct tty_struct *); void (*dcd_change)(struct tty_struct *, unsigned int, struct pps_event_time *); -- 1.7.4.1.343.ga91df --KFztAG8eRSV9hGtP-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/