Re: [PATCH AUTOSEL 5.15 34/47] tty: n_gsm: replace use of gsm_read_ea() with gsm_read_ea_val()

On 13. 10. 22, 2:21, Sasha Levin wrote:

From: Daniel Starke daniel.starke@siemens.com

[ Upstream commit 669609cea1d294f43efdd8d57ab65927df90e6df ]

Replace the use of gsm_read_ea() with gsm_read_ea_val() where applicable to improve code readability and avoid errors like in the past. See first link below for reference.

I don't think this warrants for stable. It's only a cleanup, not a fix. And it's quite intrusive.

Link: https://lore.kernel.org/all/20220504081733.3494-1-daniel.starke@siemens.com/ Link: https://lore.kernel.org/all/202208222147.WfFRmf1r-lkp@intel.com/ Reported-by: kernel test robot lkp@intel.com Signed-off-by: Daniel Starke daniel.starke@siemens.com Link: https://lore.kernel.org/r/20220831073800.7459-3-daniel.starke@siemens.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org

---

drivers/tty/n_gsm.c | 95 ++++++++++++++++++++++----------------------- 1 file changed, 47 insertions(+), 48 deletions(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c index 154697be11b0..d27247a84aab 100644 --- a/drivers/tty/n_gsm.c +++ b/drivers/tty/n_gsm.c @@ -1297,18 +1297,12 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) unsigned int modem = 0; struct gsm_dlci *dlci; int len = clen;

• int slen;

• int cl = clen; const u8 *dp = data; struct tty_struct *tty;

• while (gsm_read_ea(&addr, *dp++) == 0) {

• len--;
  

• if (len == 0)
  

• 	return;
  

• }
• /* Must be at least one byte following the EA */
• len--;
• if (len <= 0)

• len = gsm_read_ea_val(&addr, data, cl);
• if (len < 1) return;

addr >>= 1; @@ -1317,15 +1311,20 @@ static void gsm_control_modem(struct gsm_mux *gsm, const u8 *data, int clen) return; dlci = gsm->dlci[addr];

• slen = len;
• while (gsm_read_ea(&modem, *dp++) == 0) {

• len--;
  

• if (len == 0)
  

• 	return;
  

• }
• len--;

• /* Must be at least one byte following the EA */
• if ((cl - len) < 1)

• return;
  

• dp += len;
• cl -= len;
• /* get the modem status */
• len = gsm_read_ea_val(&modem, dp, cl);
• if (len < 1)

• return;
  

• tty = tty_port_tty_get(&dlci->port);

• gsm_process_modem(tty, dlci, modem, slen - len);

• gsm_process_modem(tty, dlci, modem, cl); if (tty) { tty_wakeup(tty); tty_kref_put(tty);

@@ -1819,11 +1818,10 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) struct tty_port *port = &dlci->port; struct tty_struct *tty; unsigned int modem = 0;

• int len = clen;
• int slen = 0;

• int len;

if (debug & 16)

• pr_debug("%d bytes for tty\n", len);
  

• pr_debug("%d bytes for tty\n", clen);
  

  switch (dlci->adaption) { /* Unsupported types */ case 4: /* Packetised interruptible data */

@@ -1831,24 +1829,22 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen) case 3: /* Packetised uininterruptible voice/data */ break; case 2: /* Asynchronous serial with line state in each frame */

• while (gsm_read_ea(&modem, *data++) == 0) {
  

• 	len--;
  

• 	slen++;
  

• 	if (len == 0)
  

• 		return;
  

• }
  

• len--;
  

• slen++;
  

• len = gsm_read_ea_val(&modem, data, clen);
  

• if (len < 1)
  

• 	return;
  

  tty = tty_port_tty_get(port); if (tty) {

• 	gsm_process_modem(tty, dlci, modem, slen);
  

• 	gsm_process_modem(tty, dlci, modem, len);
  tty_wakeup(tty);
  tty_kref_put(tty);
  

  }

• /* Skip processed modem data */
  

• data += len;
  

• clen -= len;
  

  fallthrough; case 1: /* Line state will go via DLCI 0 controls only */ default:

• tty_insert_flip_string(port, data, len);
  

• tty_insert_flip_string(port, data, clen);
  

  tty_flip_buffer_push(port); } }

@@ -1869,24 +1865,27 @@ static void gsm_dlci_command(struct gsm_dlci *dlci, const u8 *data, int len) { /* See what command is involved */ unsigned int command = 0;

• while (len-- > 0) {

• if (gsm_read_ea(&command, *data++) == 1) {
  

• 	int clen = *data++;
  

• 	len--;
  

• 	/* FIXME: this is properly an EA */
  

• 	clen >>= 1;
  

• 	/* Malformed command ? */
  

• 	if (clen > len)
  

• 		return;
  

• 	if (command & 1)
  

• 		gsm_control_message(dlci->gsm, command,
  

• 						data, clen);
  

• 	else
  

• 		gsm_control_response(dlci->gsm, command,
  

• 						data, clen);
  

• 	return;
  

• }
  

• }

• unsigned int clen = 0;
• unsigned int dlen;
• /* read the command */
• dlen = gsm_read_ea_val(&command, data, len);
• len -= dlen;
• data += dlen;
• /* read any control data */
• dlen = gsm_read_ea_val(&clen, data, len);
• len -= dlen;
• data += dlen;
• /* Malformed command? */
• if (clen > len)

• return;
  

• if (command & 1)

• gsm_control_message(dlci->gsm, command, data, clen);
  

• else

• gsm_control_response(dlci->gsm, command, data, clen);
  

  }

/**