Index: drivers/net/usb/gobi/README |
diff --git a/drivers/net/usb/gobi/README b/drivers/net/usb/gobi/README |
new file mode 100644 |
index 0000000000000000000000000000000000000000..113c523df59f65995b9d15a0f4ab8848c539cd8d |
--- /dev/null |
+++ b/drivers/net/usb/gobi/README |
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+Qualcomm Gobi 2000 driver |
+------------------------- |
+ |
+This directory contains a driver for the Qualcomm Gobi 2000 CDMA/GSM modem. The |
+device speaks a protocol called QMI with its host; this driver's responsibility |
+is to multiplex transactions over QMI connections. Note that the relatively |
+simple encoding defined in qmi.h and qmi.c is only the encapsulating protocol; |
+the device speaks a more complex set of protocols embodied in the closed-source |
+Gobi SDK which are necessary to use advanced features of the device. |
+Furthermore, firmware (also proprietary) is needed to make the device useful. An |
+open-source firmware loader exists: http://www.codon.org.uk/~mjg59/gobi_loader/. |
+ |
+Interfaces: |
+This driver presents two separate interfaces to userspace: |
+- usbN, an ordinary usb network interface |
+- /dev/qcqmiN, a channel to speak to the device using QMI messages |
+The latter is for use by the Gobi SDK. |
+ |
+History: |
+This driver's original incarnation (of which this is a rewrite) was released |
+under GPLv2 by Qualcomm on their Code Aurora site: |
+https://www.codeaurora.org/gitweb/quic/la/?p=kernel/msm.git;a=commit;h=b5135a880f8942f990e8c2e383f7f876beacc55b |
+ |
+Issues: |
+Help and commentary on any of the issues below would be appreciated. |
+- The locking in devqmi_close() is not threadsafe: we're walking a list of tasks |
+ without holding a lock on the list. The original driver did this and I have |
+ left it intact because I do not fully understand what's going on here. |
+- The driver seems to deadlock very occasionally (one in ~6000 reboots during |
+ stress testing). I've had no luck tracking this problem down. |