diff options
| author | Andy Walls <awalls@radix.net> | 2008-09-28 21:46:02 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2008-10-12 09:37:14 -0200 |
| commit | d267d85101c509020a12686b96cbd179deaf4ecd (patch) | |
| tree | 1a016966d11efb400ca310cd5726478053cd00a0 /drivers/media/video/cx18/cx18-driver.h | |
| parent | 7f9876785276ac7f8606f8bf53a3dae4c10b8adb (diff) | |
V4L/DVB (9110): cx18: Add default behavior of checking and retrying PCI MMIO accesses
cx18: Add default behavior of checking and retrying PCI MMIO accesses.
The concept of checking and retrying PCI MMIO accesses for better reliability
in older motherboards was suggested by Steve Toth <stoth@linuxtv.org>. This
change implements MMIO retries and the retry_mmio module parameter that is
enabled by default. Limited experiments have shown this is more reliable than
the mmio_ndelay parameter. mmio_ndelay has insignificant effect with retries
enabled.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/cx18/cx18-driver.h')
| -rw-r--r-- | drivers/media/video/cx18/cx18-driver.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/media/video/cx18/cx18-driver.h b/drivers/media/video/cx18/cx18-driver.h index 66cb748875c..80f5f563d4f 100644 --- a/drivers/media/video/cx18/cx18-driver.h +++ b/drivers/media/video/cx18/cx18-driver.h @@ -171,6 +171,7 @@ #define CX18_MAX_PGM_INDEX (400) +extern int cx18_retry_mmio; /* enable check & retry of mmio accesses */ extern int cx18_debug; @@ -344,6 +345,13 @@ struct cx18_i2c_algo_callback_data { int bus_index; /* 0 or 1 for the cx23418's 1st or 2nd I2C bus */ }; +#define CX18_MAX_MMIO_RETRIES 10 + +struct cx18_mmio_stats { + atomic_t retried_write[CX18_MAX_MMIO_RETRIES+1]; + atomic_t retried_read[CX18_MAX_MMIO_RETRIES+1]; +}; + /* Struct to hold info about cx18 cards */ struct cx18 { int num; /* board number, -1 during init! */ @@ -433,6 +441,9 @@ struct cx18 { u32 gpio_val; struct mutex gpio_lock; + /* Statistics */ + struct cx18_mmio_stats mmio_stats; + /* v4l2 and User settings */ /* codec settings */ |