package/kernel/mac80211/patches/rt2x00/022-rt2x00-check-number-of-EPROTO-errors.patch

   1 From patchwork Tue Mar 12 09:51:42 2019
   2 Content-Type: text/plain; charset="utf-8"
   3 MIME-Version: 1.0
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   5 X-Patchwork-Submitter: Stanislaw Gruszka <sgruszka@redhat.com>
   6 X-Patchwork-Id: 10848961
   7 X-Patchwork-Delegate: kvalo@adurom.com
   8 From: Stanislaw Gruszka <sgruszka@redhat.com>
   9 To: linux-wireless@vger.kernel.org
  10 Cc: =?utf-8?q?Tomislav_Po=C5=BEega?= <pozega.tomislav@gmail.com>,
  11  Daniel Golle <daniel@makrotopia.org>, Felix Fietkau <nbd@nbd.name>,
  12  Mathias Kresin <dev@kresin.me>
  13 Subject: [PATCH v3 3/4] rt2x00: check number of EPROTO errors
  14 Date: Tue, 12 Mar 2019 10:51:42 +0100
  15 Message-Id: <1552384303-29529-4-git-send-email-sgruszka@redhat.com>
  16 In-Reply-To: <1552384303-29529-1-git-send-email-sgruszka@redhat.com>
  17 References: <1552384303-29529-1-git-send-email-sgruszka@redhat.com>
  18
  19 Some USB host devices/drivers on some conditions can always return
  20 EPROTO error on submitted URBs. That can cause infinity loop in the
  21 rt2x00 driver.
  22
  23 Since we can have single EPROTO errors we can not mark as device as
  24 removed to avoid infinity loop. However we can count consecutive
  25 EPROTO errors and mark device as removed if get lot of it.
  26 I choose number 10 as threshold.
  27
  28 Reported-and-tested-by: Randy Oostdyk <linux-kernel@oostdyk.com>
  29 Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
  30 ---
  31  drivers/net/wireless/ralink/rt2x00/rt2x00.h    |  1 +
  32  drivers/net/wireless/ralink/rt2x00/rt2x00usb.c | 22 +++++++++++++++++++---
  33  2 files changed, 20 insertions(+), 3 deletions(-)
  34
  35 --- a/drivers/net/wireless/ralink/rt2x00/rt2x00.h
  36 +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00.h
  37 @@ -1017,6 +1017,7 @@ struct rt2x00_dev {
  38         unsigned int extra_tx_headroom;
  39
  40         struct usb_anchor *anchor;
  41 +       unsigned int num_proto_errs;
  42
  43         /* Clock for System On Chip devices. */
  44         struct clk *clk;
  45 --- a/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
  46 +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c
  47 @@ -31,6 +31,22 @@
  48  #include "rt2x00.h"
  49  #include "rt2x00usb.h"
  50
  51 +static bool rt2x00usb_check_usb_error(struct rt2x00_dev *rt2x00dev, int status)
  52 +{
  53 +       if (status == -ENODEV || status == -ENOENT)
  54 +               return true;
  55 +
  56 +       if (status == -EPROTO || status == -ETIMEDOUT)
  57 +               rt2x00dev->num_proto_errs++;
  58 +       else
  59 +               rt2x00dev->num_proto_errs = 0;
  60 +
  61 +       if (rt2x00dev->num_proto_errs > 3)
  62 +               return true;
  63 +
  64 +       return false;
  65 +}
  66 +
  67  /*
  68   * Interfacing with the HW.
  69   */
  70 @@ -57,7 +73,7 @@ int rt2x00usb_vendor_request(struct rt2x
  71                 if (status >= 0)
  72                         return 0;
  73
  74 -               if (status == -ENODEV || status == -ENOENT) {
  75 +               if (rt2x00usb_check_usb_error(rt2x00dev, status)) {
  76                         /* Device has disappeared. */
  77                         clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
  78                         break;
  79 @@ -321,7 +337,7 @@ static bool rt2x00usb_kick_tx_entry(stru
  80
  81         status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
  82         if (status) {
  83 -               if (status == -ENODEV || status == -ENOENT)
  84 +               if (rt2x00usb_check_usb_error(rt2x00dev, status))
  85                         clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
  86                 set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
  87                 rt2x00lib_dmadone(entry);
  88 @@ -410,7 +426,7 @@ static bool rt2x00usb_kick_rx_entry(stru
  89
  90         status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
  91         if (status) {
  92 -               if (status == -ENODEV || status == -ENOENT)
  93 +               if (rt2x00usb_check_usb_error(rt2x00dev, status))
  94                         clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
  95                 set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
  96                 rt2x00lib_dmadone(entry);