Messages in this thread | | | From | Rahul Tanwar <> | Subject | Re: [PATCH RESEND v2 2/5] clk: mxl: Remove unnecessary spinlocks | Date | Thu, 29 Sep 2022 05:37:12 +0000 |
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On 29/9/2022 8:16 am, Stephen Boyd wrote: > This email was sent from outside of MaxLinear. > > > Quoting Rahul Tanwar (2022-09-21 23:24:25) >> This driver is now switched from direct readl/writel based register >> access to regmap based register acceess. Regmap already has its own >> lock to serialize the register accesses across multiple cores. >> >> Hence, there is no need for additional spinlocks in the driver. >> Remove all spinlocks which are no longer required. > > Can you confirm that the driver doesn't do a read, modify, write (rmw) > sequence where during the modification another CPU can rmw and corrupt > the previous "read"?
For rmw, driver uses regmap_update_bits() API. All regmap API's use their own spinlocks before doing any read or write or rmw.
Patch 1/5 switches from direct readl/writel to regmap based API's for register read/write/rmw in which case additional driver spinlock becomes redundant. So this patch 2/5 removes redundant driver spin locks.
Thanks, Rahul
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