[ar71xx] preliminary support for the Ubiquiti RouterStation Pro
[openwrt.git] / target / linux / s3c24xx / patches-2.6.24 / 1185-fix-pcf50633-interrupt-work-enforce-wait-on-resume-c.patch
1 From ac949375c7ef5882e8d3ea4f4a165b2fce943f21 Mon Sep 17 00:00:00 2001
2 From: Andy Green <andy@openmoko.com>
3 Date: Wed, 2 Jul 2008 22:39:56 +0100
4 Subject: [PATCH] fix-pcf50633-interrupt-work-enforce-wait-on-resume-completion.patch
5
6 Improve pcf50633 interrupt service scheduling to enforce only servicing
7 when resume action is completed
8
9 Signed-off-by: Andy Green <andy@openmoko.com>
10 ---
11 drivers/i2c/chips/pcf50633.c | 67 ++++++++++++++++++++++++++++++------------
12 1 files changed, 48 insertions(+), 19 deletions(-)
13
14 diff --git a/drivers/i2c/chips/pcf50633.c b/drivers/i2c/chips/pcf50633.c
15 index 4d92c84..33e2eaf 100644
16 --- a/drivers/i2c/chips/pcf50633.c
17 +++ b/drivers/i2c/chips/pcf50633.c
18 @@ -656,6 +656,26 @@ static void pcf50633_work(struct work_struct *work)
19
20 mutex_lock(&pcf->working_lock);
21 pcf->working = 1;
22 +
23 + dev_info(&pcf->client.dev, "pcf50633_work called with suspended = %d\n",
24 + pcf->have_been_suspended);
25 +
26 + /*
27 + * If we are inside suspend -> resume completion time we don't attempt
28 + * service until we have fully resumed. Although we could talk to the
29 + * device as soon as I2C is up, the regs in the device which we might
30 + * choose to modify as part of the service action have not been
31 + * reloaded with their pre-suspend states yet. Therefore we will
32 + * defer our service if we are called like that until our resume has
33 + * completed.
34 + */
35 +
36 + if (pcf->have_been_suspended && (pcf->have_been_suspended < 2)) {
37 + dev_info(&pcf->client.dev, "rescheduling, suspended = %d\n",
38 + pcf->have_been_suspended);
39 + goto reschedule;
40 + }
41 +
42 /*
43 * datasheet says we have to read the five IRQ
44 * status regs in one transaction
45 @@ -663,30 +683,25 @@ static void pcf50633_work(struct work_struct *work)
46 ret = i2c_smbus_read_i2c_block_data(&pcf->client, PCF50633_REG_INT1, 5,
47 pcfirq);
48 if (ret != 5) {
49 - DEBUGP("Oh crap PMU IRQ register read failed -- "
50 - "retrying later %d\n", ret);
51 + dev_info(&pcf->client.dev,
52 + "Oh crap PMU IRQ register read failed -- "
53 + "retrying later %d\n", ret);
54 /*
55 - * this situation can happen during resume, just defer
56 - * handling the interrupt until enough I2C is up we can
57 - * actually talk to the PMU. We can't just ignore this
58 - * because we are on a falling edge interrupt and our
59 - * PMU interrupt source does not clear until we read these
60 - * interrupt source registers.
61 + * it shouldn't fail, we no longer attempt to use I2C while
62 + * it can be suspended. But we don't have much option but to
63 + * retry if if it ever did fail, because if we don't service
64 + * the interrupt to clear it, we will never see another PMU
65 + * interrupt edge.
66 */
67 - if (!schedule_work(&pcf->work) && !pcf->working)
68 - dev_dbg(&pcf->client.dev, "work item may be lost\n");
69 -
70 - /* we don't put the device here, hold it for next time */
71 - mutex_unlock(&pcf->working_lock);
72 - /* don't spew, delaying whatever else is happening */
73 - msleep(1);
74 - return;
75 + goto reschedule;
76 }
77
78 /* hey did we just resume? */
79
80 if (pcf->have_been_suspended) {
81 + /* resume is officially over now then */
82 pcf->have_been_suspended = 0;
83 +
84 /*
85 * grab a copy of resume interrupt reasons
86 * from pcf50633 POV
87 @@ -1045,6 +1060,19 @@ static void pcf50633_work(struct work_struct *work)
88 input_sync(pcf->input_dev);
89 put_device(&pcf->client.dev);
90 mutex_unlock(&pcf->working_lock);
91 +
92 + return;
93 +
94 +reschedule:
95 + /* don't spew, delaying whatever else is happening */
96 + msleep(100);
97 +
98 + dev_info(&pcf->client.dev, "rescheduling interrupt service\n");
99 + if (!schedule_work(&pcf->work))
100 + dev_err(&pcf->client.dev, "int service reschedule failed\n");
101 +
102 + /* we don't put the device here, hold it for next time */
103 + mutex_unlock(&pcf->working_lock);
104 }
105
106 static irqreturn_t pcf50633_irq(int irq, void *_pcf)
107 @@ -1052,10 +1080,11 @@ static irqreturn_t pcf50633_irq(int irq, void *_pcf)
108 struct pcf50633_data *pcf = _pcf;
109
110 DEBUGP("entering(irq=%u, pcf=%p): scheduling work\n", irq, _pcf);
111 + dev_info(&pcf->client.dev, "pcf50633_irq scheduling work\n");
112
113 get_device(&pcf->client.dev);
114 if (!schedule_work(&pcf->work) && !pcf->working)
115 - dev_dbg(&pcf->client.dev, "work item may be lost\n");
116 + dev_err(&pcf->client.dev, "work item may be lost\n");
117
118 return IRQ_HANDLED;
119 }
120 @@ -2244,9 +2273,9 @@ static int pcf50633_suspend(struct device *dev, pm_message_t state)
121 int pcf50633_ready(struct pcf50633_data *pcf)
122 {
123 if (!pcf)
124 - return -EBUSY;
125 + return -EACCES;
126
127 - if (pcf->have_been_suspended)
128 + if (pcf->have_been_suspended && (pcf->have_been_suspended < 3))
129 return -EBUSY;
130
131 return 0;
132 --
133 1.5.6.5
134
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