On Fri, Mar 26, 2021 at 11:27 PM Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > On Sat, Mar 6, 2021 at 4:08 PM Syed Nayyar Waris <syednwaris@xxxxxxxxx> wrote: > > > > This patch reimplements the xgpio_set_multiple() function in > > drivers/gpio/gpio-xilinx.c to use the new generic functions: > > bitmap_get_value() and bitmap_set_value(). The code is now simpler > > to read and understand. Moreover, instead of looping for each bit > > in xgpio_set_multiple() function, now we can check each channel at > > a time and save cycles. > > ... > > > + u32 *const state = chip->gpio_state; > > + unsigned int *const width = chip->gpio_width; > > > + > > Extra blank line. > > > + DECLARE_BITMAP(old, 64); > > + DECLARE_BITMAP(new, 64); > > + DECLARE_BITMAP(changed, 64); > > > + spin_lock_irqsave(&chip->gpio_lock[0], flags); > > + spin_lock(&chip->gpio_lock[1]); > > I understand why this is done at the top of the function in the original code. > I do not understand why you put some operations under spin lock. > > Have you checked what each of these spin locks protects? > Please check and try to lock as minimum as possible. > > > + bitmap_set_value(old, 64, state[0], width[0], 0); > > + bitmap_set_value(old, 64, state[1], width[1], width[0]); > > + bitmap_replace(new, old, bits, mask, gc->ngpio); > > + > > + bitmap_set_value(old, 64, state[0], 32, 0); > > + bitmap_set_value(old, 64, state[1], 32, 32); > > + state[0] = bitmap_get_value(new, 0, width[0]); > > + state[1] = bitmap_get_value(new, width[0], width[1]); > > + bitmap_set_value(new, 64, state[0], 32, 0); > > + bitmap_set_value(new, 64, state[1], 32, 32); > > + bitmap_xor(changed, old, new, 64); > > Original code and this is cryptic. Can you add a few comments > explaining what is going on here? > > > + spin_unlock(&chip->gpio_lock[1]); > > + spin_unlock_irqrestore(&chip->gpio_lock[0], flags); > > -- > With Best Regards, > Andy Shevchenko Have removed the extra line and added comments. Regarding locking - I see that now there is just a single lock available instead of 2 locks. Have made necessary changes. Thanks https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/gpio/gpio-xilinx.c?id=37ef334680800263b32bb96a5156a4b47f0244a2 Regards Syed Nayyar Waris
