On Tue, May 05, 2020 at 05:03:27PM +0100, Emil Velikov wrote:
Currently the function heap allocates when we have any payload. Where in many case the payload is 1 byte - ouch.
From casual observation, vast majority of the payloads are smaller than 8 bytes - so use a stack array tx[8] to avoid the senseless kmalloc and kfree dance.
Cc: Jani Nikula jani.nikula@intel.com Cc: Thierry Reding treding@nvidia.com Signed-off-by: Emil Velikov emil.velikov@collabora.com
drivers/gpu/drm/drm_mipi_dsi.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 55531895dde6..b96d5b4629d7 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -748,26 +748,26 @@ ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd, { ssize_t err; size_t size;
- u8 stack_tx[8]; u8 *tx;
- if (len > 0) {
size = 1 + len;
- size = 1 + len;
- if (len > ARRAY_SIZE(stack_tx) - 1) {
I think it would be clearer to do:
if (size > ARRAY_SIZE(stack_tx))
but either way:
Reviewed-by: Thierry Reding treding@nvidia.com