From patchwork Tue Mar 12 09:51:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislaw Gruszka X-Patchwork-Id: 10848961 X-Patchwork-Delegate: kvalo@adurom.com From: Stanislaw Gruszka To: linux-wireless@vger.kernel.org Cc: =?utf-8?q?Tomislav_Po=C5=BEega?= , Daniel Golle , Felix Fietkau , Mathias Kresin Subject: [PATCH v3 3/4] rt2x00: check number of EPROTO errors Date: Tue, 12 Mar 2019 10:51:42 +0100 Message-Id: <1552384303-29529-4-git-send-email-sgruszka@redhat.com> In-Reply-To: <1552384303-29529-1-git-send-email-sgruszka@redhat.com> References: <1552384303-29529-1-git-send-email-sgruszka@redhat.com> Some USB host devices/drivers on some conditions can always return EPROTO error on submitted URBs. That can cause infinity loop in the rt2x00 driver. Since we can have single EPROTO errors we can not mark as device as removed to avoid infinity loop. However we can count consecutive EPROTO errors and mark device as removed if get lot of it. I choose number 10 as threshold. Reported-and-tested-by: Randy Oostdyk Signed-off-by: Stanislaw Gruszka --- drivers/net/wireless/ralink/rt2x00/rt2x00.h | 1 + drivers/net/wireless/ralink/rt2x00/rt2x00usb.c | 22 +++++++++++++++++++--- 2 files changed, 20 insertions(+), 3 deletions(-) --- a/drivers/net/wireless/ralink/rt2x00/rt2x00.h +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00.h @@ -1016,6 +1016,7 @@ struct rt2x00_dev { unsigned int extra_tx_headroom; struct usb_anchor *anchor; + unsigned int num_proto_errs; /* Clock for System On Chip devices. */ struct clk *clk; --- a/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c +++ b/drivers/net/wireless/ralink/rt2x00/rt2x00usb.c @@ -31,6 +31,22 @@ #include "rt2x00.h" #include "rt2x00usb.h" +static bool rt2x00usb_check_usb_error(struct rt2x00_dev *rt2x00dev, int status) +{ + if (status == -ENODEV || status == -ENOENT) + return true; + + if (status == -EPROTO || status == -ETIMEDOUT) + rt2x00dev->num_proto_errs++; + else + rt2x00dev->num_proto_errs = 0; + + if (rt2x00dev->num_proto_errs > 3) + return true; + + return false; +} + /* * Interfacing with the HW. */ @@ -57,7 +73,7 @@ int rt2x00usb_vendor_request(struct rt2x if (status >= 0) return 0; - if (status == -ENODEV || status == -ENOENT) { + if (rt2x00usb_check_usb_error(rt2x00dev, status)) { /* Device has disappeared. */ clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags); break; @@ -321,7 +337,7 @@ static bool rt2x00usb_kick_tx_entry(stru status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC); if (status) { - if (status == -ENODEV || status == -ENOENT) + if (rt2x00usb_check_usb_error(rt2x00dev, status)) clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags); set_bit(ENTRY_DATA_IO_FAILED, &entry->flags); rt2x00lib_dmadone(entry); @@ -410,7 +426,7 @@ static bool rt2x00usb_kick_rx_entry(stru status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC); if (status) { - if (status == -ENODEV || status == -ENOENT) + if (rt2x00usb_check_usb_error(rt2x00dev, status)) clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags); set_bit(ENTRY_DATA_IO_FAILED, &entry->flags); rt2x00lib_dmadone(entry);