diff options
| author | Jani Nikula <jani.nikula@intel.com> | 2025-08-28 15:20:48 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2025-09-04 14:02:58 +0300 |
| commit | 11080a5ea877d7da163a93975559b9607f629d49 (patch) | |
| tree | 3860e338e6c56400b7361c646d4f0092d26c3ac8 | |
| parent | 0399a3368503c75043afbb680071dabc723aa9d7 (diff) | |
drm/i915/gmbus: use generic poll_timeout*() instead of wait_for*()
Prefer generic poll helpers over i915 custom helpers.
The "two tier" wait_for_us() + wait_for() combination appeared without
much explanation in commit 4e6c2d58ba86 ("drm/i915: Take forcewake once
for the entire GMBUS transaction"). Try to mimic roughly the same with
the generic helpers.
wait_for_us() with 10 us or shorter timeouts ends up in
_wait_for_atomic(). Thus use poll_timeout_us_atomic() for the first try,
with the same 2 us timeout and no sleep.
For the fallback, the functional change is losing the exponentially
growing sleep of wait_for(), which used to be 10, 20, 40, ..., 640, and
1280 us. Use an arbitrary constant 500 us sleep instead. The timeout
remains at 50 ms.
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Link: https://lore.kernel.org/r/564b397352c53a1116519fb2d53050c0426bc0dc.1756383233.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_gmbus.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_gmbus.c b/drivers/gpu/drm/i915/display/intel_gmbus.c index 063335053d13..358210adb8f8 100644 --- a/drivers/gpu/drm/i915/display/intel_gmbus.c +++ b/drivers/gpu/drm/i915/display/intel_gmbus.c @@ -30,13 +30,13 @@ #include <linux/export.h> #include <linux/i2c-algo-bit.h> #include <linux/i2c.h> +#include <linux/iopoll.h> #include <drm/display/drm_hdcp_helper.h> #include "i915_drv.h" #include "i915_irq.h" #include "i915_reg.h" -#include "i915_utils.h" #include "intel_de.h" #include "intel_display_regs.h" #include "intel_display_types.h" @@ -415,11 +415,14 @@ static int gmbus_wait(struct intel_display *display, u32 status, u32 irq_en) intel_de_write_fw(display, GMBUS4(display), irq_en); status |= GMBUS_SATOER; - ret = wait_for_us((gmbus2 = intel_de_read_fw(display, GMBUS2(display))) & status, - 2); + + ret = poll_timeout_us_atomic(gmbus2 = intel_de_read_fw(display, GMBUS2(display)), + gmbus2 & status, + 0, 2, false); if (ret) - ret = wait_for((gmbus2 = intel_de_read_fw(display, GMBUS2(display))) & status, - 50); + ret = poll_timeout_us(gmbus2 = intel_de_read_fw(display, GMBUS2(display)), + gmbus2 & status, + 500, 50 * 1000, false); intel_de_write_fw(display, GMBUS4(display), 0); remove_wait_queue(&display->gmbus.wait_queue, &wait); |