diff options
| author | Andy Walls <awalls@radix.net> | 2008-11-02 16:15:28 -0500 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2008-12-30 06:38:00 -0500 |
| commit | f7823f8f437fbbd41155f2312ef17e471199b706 (patch) | |
| tree | 245f1a91956f553ce387e6caa10c875b3f4316c4 /drivers/media/video/cx18/cx18-driver.h | |
| parent | f2e52cd17622eed39576f113b77bbd18c577e308 (diff) | |
V4L/DVB (9513): cx18: Reduce number of mmio read retries
cx18: Reduce number of mmio read retries to improve performance. Experiments
have shown 2 things: read retries never improve the result of a suspect mmio
read from the CX23418 (the result stays all 0xff's), and that most of the
suspected read failures are actually proper reads of values that should be
all 0xff's. This change reduces the number of read retries and keeps the
count separate from write retries.
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 | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/media/video/cx18/cx18-driver.h b/drivers/media/video/cx18/cx18-driver.h index bbdd5f25041d..fe9e5bb979e0 100644 --- a/drivers/media/video/cx18/cx18-driver.h +++ b/drivers/media/video/cx18/cx18-driver.h | |||
| @@ -353,11 +353,12 @@ struct cx18_i2c_algo_callback_data { | |||
| 353 | int bus_index; /* 0 or 1 for the cx23418's 1st or 2nd I2C bus */ | 353 | int bus_index; /* 0 or 1 for the cx23418's 1st or 2nd I2C bus */ |
| 354 | }; | 354 | }; |
| 355 | 355 | ||
| 356 | #define CX18_MAX_MMIO_RETRIES 10 | 356 | #define CX18_MAX_MMIO_WR_RETRIES 10 |
| 357 | #define CX18_MAX_MMIO_RD_RETRIES 2 | ||
| 357 | 358 | ||
| 358 | struct cx18_mmio_stats { | 359 | struct cx18_mmio_stats { |
| 359 | atomic_t retried_write[CX18_MAX_MMIO_RETRIES+1]; | 360 | atomic_t retried_write[CX18_MAX_MMIO_WR_RETRIES+1]; |
| 360 | atomic_t retried_read[CX18_MAX_MMIO_RETRIES+1]; | 361 | atomic_t retried_read[CX18_MAX_MMIO_RD_RETRIES+1]; |
| 361 | }; | 362 | }; |
| 362 | 363 | ||
| 363 | /* Struct to hold info about cx18 cards */ | 364 | /* Struct to hold info about cx18 cards */ |