Re: [PATCH 6/6] soc: fsl: qe: fix sparse warnings for ucc_slow.c
On Mon, Mar 16, 2020 at 4:08 PM Rasmus Villemoes wrote: > > On 12/03/2020 23.28, Li Yang wrote: > > Fixes the following sparse warnings: > > > [snip] > > > > Also removed the unneccessary clearing for kzalloc'ed structure. > > Please don't mix that in the same patch, do it in a preparatory patch. > That makes reviewing much easier. Thanks for the review. One of the few lines removed are actually causing sparse warning, that's why I changed this together with the sparse fixes. I can add all the lines removed in the log for better record. > > > > > /* Get PRAM base */ > > uccs->us_pram_offset = > > @@ -231,24 +224,24 @@ int ucc_slow_init(struct ucc_slow_info * us_info, > > struct ucc_slow_private ** ucc > > /* clear bd buffer */ > > qe_iowrite32be(0, >buf); > > /* set bd status and length */ > > - qe_iowrite32be(0, (u32 *)bd); > > + qe_iowrite32be(0, (u32 __iomem *)bd); > > It's cleaner to do two qe_iowrite16be to >status and >length, > that avoids the casting altogether. It probably is cleaner, but also slower for the bd manipulation that can be in the hot path. The QE code has been using this way to access/update the bd status and length together for a long time. And I remembered that it could help to prevent synchronization issues for accessing status and length separately. It is probably cleaner to change the data structure to use union for accessing status and length together. But that will need a big change to update all the current users of the structure which I don't have the time to do right now. > > > bd++; > > } > > /* for last BD set Wrap bit */ > > qe_iowrite32be(0, >buf); > > - qe_iowrite32be(cpu_to_be32(T_W), (u32 *)bd); > > + qe_iowrite32be(T_W, (u32 __iomem *)bd); > > Yeah, and this is why. Who can actually keep track of where that bit > ends up being set with that casting going on. Please use > qe_iowrite16be() with an appropriately modified constant to the > appropriate field instead of these games. > > And if the hardware doesn't support 16 bit writes, the definition of > struct qe_bd is wrong and should have a single __be32 status_length > field, with appropriate accessors defined. Same comment as above. > > > /* Init Rx bds */ > > bd = uccs->rx_bd = qe_muram_addr(uccs->rx_base_offset); > > for (i = 0; i < us_info->rx_bd_ring_len - 1; i++) { > > /* set bd status and length */ > > - qe_iowrite32be(0, (u32 *)bd); > > + qe_iowrite32be(0, (u32 __iomem *)bd); > > Same. > > > /* clear bd buffer */ > > qe_iowrite32be(0, >buf); > > bd++; > > } > > /* for last BD set Wrap bit */ > > - qe_iowrite32be(cpu_to_be32(R_W), (u32 *)bd); > > + qe_iowrite32be(R_W, (u32 __iomem *)bd); > > Same. > > > qe_iowrite32be(0, >buf); > > > > /* Set GUMR (For more details see the hardware spec.). */ > > @@ -273,8 +266,8 @@ int ucc_slow_init(struct ucc_slow_info * us_info, > > struct ucc_slow_private ** ucc > > qe_iowrite32be(gumr, _regs->gumr_h); > > > > /* gumr_l */ > > - gumr = us_info->tdcr | us_info->rdcr | us_info->tenc | us_info->renc | > > - us_info->diag | us_info->mode; > > + gumr = (u32)us_info->tdcr | (u32)us_info->rdcr | (u32)us_info->tenc | > > +(u32)us_info->renc | (u32)us_info->diag | (u32)us_info->mode; > > Are the tdcr, rdcr, tenc, renc fields actually set anywhere (the same > for the diag and mode, but word-grepping for those give way too many > false positives)? They seem to be a somewhat pointless split out of the > bitfields of gumr_l, and not populated anywhere?. That's not directly > related to this patch, of course, but getting rid of them first (if they > are indeed completely unused) might make the sparse cleanup a little > simpler. I would agree with you that is not neccessary to create different enum types for these bits in the same register in the first place. But I would like to prevent aggressive cleanups of this driver for old hardware that is becoming harder and harder to be thoroughly tested right now. These fields are probably not used by the in tree ucc_uart driver right now. But as a generic library for QE, I think it is harmless to keep these simple code there for potentially customized version of the uart driver or other ucc slow drivers. Regards, Leo
Re: [PATCH 6/6] soc: fsl: qe: fix sparse warnings for ucc_slow.c
On 12/03/2020 23.28, Li Yang wrote: > Fixes the following sparse warnings: > [snip] > > Also removed the unneccessary clearing for kzalloc'ed structure. Please don't mix that in the same patch, do it in a preparatory patch. That makes reviewing much easier. > > /* Get PRAM base */ > uccs->us_pram_offset = > @@ -231,24 +224,24 @@ int ucc_slow_init(struct ucc_slow_info * us_info, > struct ucc_slow_private ** ucc > /* clear bd buffer */ > qe_iowrite32be(0, >buf); > /* set bd status and length */ > - qe_iowrite32be(0, (u32 *)bd); > + qe_iowrite32be(0, (u32 __iomem *)bd); It's cleaner to do two qe_iowrite16be to >status and >length, that avoids the casting altogether. > bd++; > } > /* for last BD set Wrap bit */ > qe_iowrite32be(0, >buf); > - qe_iowrite32be(cpu_to_be32(T_W), (u32 *)bd); > + qe_iowrite32be(T_W, (u32 __iomem *)bd); Yeah, and this is why. Who can actually keep track of where that bit ends up being set with that casting going on. Please use qe_iowrite16be() with an appropriately modified constant to the appropriate field instead of these games. And if the hardware doesn't support 16 bit writes, the definition of struct qe_bd is wrong and should have a single __be32 status_length field, with appropriate accessors defined. > /* Init Rx bds */ > bd = uccs->rx_bd = qe_muram_addr(uccs->rx_base_offset); > for (i = 0; i < us_info->rx_bd_ring_len - 1; i++) { > /* set bd status and length */ > - qe_iowrite32be(0, (u32 *)bd); > + qe_iowrite32be(0, (u32 __iomem *)bd); Same. > /* clear bd buffer */ > qe_iowrite32be(0, >buf); > bd++; > } > /* for last BD set Wrap bit */ > - qe_iowrite32be(cpu_to_be32(R_W), (u32 *)bd); > + qe_iowrite32be(R_W, (u32 __iomem *)bd); Same. > qe_iowrite32be(0, >buf); > > /* Set GUMR (For more details see the hardware spec.). */ > @@ -273,8 +266,8 @@ int ucc_slow_init(struct ucc_slow_info * us_info, struct > ucc_slow_private ** ucc > qe_iowrite32be(gumr, _regs->gumr_h); > > /* gumr_l */ > - gumr = us_info->tdcr | us_info->rdcr | us_info->tenc | us_info->renc | > - us_info->diag | us_info->mode; > + gumr = (u32)us_info->tdcr | (u32)us_info->rdcr | (u32)us_info->tenc | > +(u32)us_info->renc | (u32)us_info->diag | (u32)us_info->mode; Are the tdcr, rdcr, tenc, renc fields actually set anywhere (the same for the diag and mode, but word-grepping for those give way too many false positives)? They seem to be a somewhat pointless split out of the bitfields of gumr_l, and not populated anywhere?. That's not directly related to this patch, of course, but getting rid of them first (if they are indeed completely unused) might make the sparse cleanup a little simpler. Rasmus
[PATCH 6/6] soc: fsl: qe: fix sparse warnings for ucc_slow.c
Fixes the following sparse warnings: drivers/soc/fsl/qe/ucc_slow.c:78:17: warning: incorrect type in assignment (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:78:17:expected struct ucc_slow *us_regs drivers/soc/fsl/qe/ucc_slow.c:78:17:got struct ucc_slow [noderef] *us_regs drivers/soc/fsl/qe/ucc_slow.c:81:18: warning: incorrect type in argument 1 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:81:18:expected void const volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:81:18:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:90:9: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:90:9:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:90:9:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:99:17: warning: incorrect type in assignment (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:99:17:expected struct ucc_slow *us_regs drivers/soc/fsl/qe/ucc_slow.c:99:17:got struct ucc_slow [noderef] *us_regs drivers/soc/fsl/qe/ucc_slow.c:102:18: warning: incorrect type in argument 1 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:102:18:expected void const volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:102:18:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:111:9: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:111:9:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:111:9:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:172:28: warning: Using plain integer as NULL pointer drivers/soc/fsl/qe/ucc_slow.c:174:25: warning: cast removes address space '' of expression drivers/soc/fsl/qe/ucc_slow.c:175:25: warning: cast removes address space '' of expression drivers/soc/fsl/qe/ucc_slow.c:194:23: warning: incorrect type in assignment (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:194:23:expected struct ucc_slow_pram *us_pram drivers/soc/fsl/qe/ucc_slow.c:194:23:got void [noderef] * drivers/soc/fsl/qe/ucc_slow.c:204:9: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:204:9:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:204:9:got restricted __be16 * drivers/soc/fsl/qe/ucc_slow.c:229:41: warning: incorrect type in assignment (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:229:41:expected struct qe_bd *tx_bd drivers/soc/fsl/qe/ucc_slow.c:229:41:got void [noderef] * drivers/soc/fsl/qe/ucc_slow.c:232:17: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:232:17:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:232:17:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:234:17: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:234:17:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:234:17:got unsigned int [usertype] * drivers/soc/fsl/qe/ucc_slow.c:238:9: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:238:9:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:238:9:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:239:9: warning: cast from restricted __be32 drivers/soc/fsl/qe/ucc_slow.c:239:9: warning: incorrect type in argument 1 (different base types) drivers/soc/fsl/qe/ucc_slow.c:239:9:expected unsigned int [usertype] val drivers/soc/fsl/qe/ucc_slow.c:239:9:got restricted __be32 [usertype] drivers/soc/fsl/qe/ucc_slow.c:239:9: warning: cast from restricted __be32 drivers/soc/fsl/qe/ucc_slow.c:239:9: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:239:9:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:239:9:got unsigned int [usertype] * drivers/soc/fsl/qe/ucc_slow.c:242:26: warning: incorrect type in assignment (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:242:26:expected struct qe_bd *rx_bd drivers/soc/fsl/qe/ucc_slow.c:242:26:got void [noderef] * drivers/soc/fsl/qe/ucc_slow.c:245:17: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:245:17:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:245:17:got unsigned int [usertype] * drivers/soc/fsl/qe/ucc_slow.c:247:17: warning: incorrect type in argument 2 (different address spaces) drivers/soc/fsl/qe/ucc_slow.c:247:17:expected void volatile [noderef] *addr drivers/soc/fsl/qe/ucc_slow.c:247:17:got restricted __be32 * drivers/soc/fsl/qe/ucc_slow.c:251:9: warning: cast from restricted __be32 drivers/soc/fsl/qe/ucc_slow.c:251:9: warning: incorrect type in argument 1 (different base types) drivers/soc/fsl/qe/ucc_slow.c:251:9:expected unsigned int [usertype] val drivers/soc/fsl/qe/ucc_slow.c:251:9: